diff --git a/ivy/src/main/scala/org/apache/ivy/plugins/parser/m2/ReplaceMavenConfigurationMappings.scala b/ivy/src/main/scala/org/apache/ivy/plugins/parser/m2/ReplaceMavenConfigurationMappings.scala
index 0e85d5b6b..e59bd174e 100644
--- a/ivy/src/main/scala/org/apache/ivy/plugins/parser/m2/ReplaceMavenConfigurationMappings.scala
+++ b/ivy/src/main/scala/org/apache/ivy/plugins/parser/m2/ReplaceMavenConfigurationMappings.scala
@@ -38,7 +38,7 @@ object ReplaceMavenConfigurationMappings {
     // NOTE - This code is copied from org.apache.ivy.plugins.parser.m2.PomModuleDescriptorBuilder
     // except with altered default configurations...
     REPLACEMENT_MAPPINGS.put("compile", new PomModuleDescriptorBuilder.ConfMapper {
-      def addMappingConfs(dd: DefaultDependencyDescriptor, isOptional: Boolean) {
+      def addMappingConfs(dd: DefaultDependencyDescriptor, isOptional: Boolean): Unit = {
         if (isOptional) {
           dd.addDependencyConfiguration("optional", "compile(*)")
           // FIX - Here we take a mroe conservative approach of depending on the compile configuration if master isn't there.
@@ -52,7 +52,7 @@ object ReplaceMavenConfigurationMappings {
       }
     })
     REPLACEMENT_MAPPINGS.put("provided", new PomModuleDescriptorBuilder.ConfMapper {
-      def addMappingConfs(dd: DefaultDependencyDescriptor, isOptional: Boolean) {
+      def addMappingConfs(dd: DefaultDependencyDescriptor, isOptional: Boolean): Unit = {
         if (isOptional) {
           dd.addDependencyConfiguration("optional", "compile(*)")
           dd.addDependencyConfiguration("optional", "provided(*)")
@@ -70,7 +70,7 @@ object ReplaceMavenConfigurationMappings {
     })
 
     REPLACEMENT_MAPPINGS.put("runtime", new PomModuleDescriptorBuilder.ConfMapper {
-      def addMappingConfs(dd: DefaultDependencyDescriptor, isOptional: Boolean) {
+      def addMappingConfs(dd: DefaultDependencyDescriptor, isOptional: Boolean): Unit = {
         if (isOptional) {
           dd.addDependencyConfiguration("optional", "compile(*)")
           dd.addDependencyConfiguration("optional", "provided(*)")
@@ -86,7 +86,7 @@ object ReplaceMavenConfigurationMappings {
     })
 
     REPLACEMENT_MAPPINGS.put("test", new PomModuleDescriptorBuilder.ConfMapper {
-      def addMappingConfs(dd: DefaultDependencyDescriptor, isOptional: Boolean) {
+      def addMappingConfs(dd: DefaultDependencyDescriptor, isOptional: Boolean): Unit = {
         dd.addDependencyConfiguration("test", "runtime(*)")
         // FIX - Here we take a mroe conservative approach of depending on the compile configuration if master isn't there.
         dd.addDependencyConfiguration("test", "master(compile)")
@@ -94,7 +94,7 @@ object ReplaceMavenConfigurationMappings {
     })
 
     REPLACEMENT_MAPPINGS.put("system", new PomModuleDescriptorBuilder.ConfMapper {
-      def addMappingConfs(dd: DefaultDependencyDescriptor, isOptional: Boolean) {
+      def addMappingConfs(dd: DefaultDependencyDescriptor, isOptional: Boolean): Unit = {
         // FIX - Here we take a mroe conservative approach of depending on the compile configuration if master isn't there.
         dd.addDependencyConfiguration("system", "master(compile)")
       }
@@ -115,4 +115,4 @@ object ReplaceMavenConfigurationMappings {
         throw new RuntimeException("FAILURE to install Ivy maven hooks.  Your ivy-maven interaction may suffer resolution errors", e)
     }
   }
-}
\ No newline at end of file
+}
diff --git a/ivy/src/main/scala/sbt/ConflictWarning.scala b/ivy/src/main/scala/sbt/ConflictWarning.scala
index 082a478b6..a4e011736 100644
--- a/ivy/src/main/scala/sbt/ConflictWarning.scala
+++ b/ivy/src/main/scala/sbt/ConflictWarning.scala
@@ -28,10 +28,10 @@ object ConflictWarning {
   @deprecated("Warning on evicted modules is no longer done, so this is the same as `default`.  Use a standard Ivy conflict manager.", "0.13.0")
   def strict(label: String): ConflictWarning = ConflictWarning(label, Level.Error, true)
 
-  def apply(config: ConflictWarning, report: UpdateReport, log: Logger) {
+  def apply(config: ConflictWarning, report: UpdateReport, log: Logger): Unit = {
     processCrossVersioned(config, report, log)
   }
-  private[this] def processCrossVersioned(config: ConflictWarning, report: UpdateReport, log: Logger) {
+  private[this] def processCrossVersioned(config: ConflictWarning, report: UpdateReport, log: Logger): Unit = {
     val crossMismatches = crossVersionMismatches(report)
     if (crossMismatches.nonEmpty) {
       val pre = s"Modules were resolved with conflicting cross-version suffixes in ${config.label}:\n   "
diff --git a/ivy/src/main/scala/sbt/ConvertResolver.scala b/ivy/src/main/scala/sbt/ConvertResolver.scala
index a01a51380..9768241d5 100644
--- a/ivy/src/main/scala/sbt/ConvertResolver.scala
+++ b/ivy/src/main/scala/sbt/ConvertResolver.scala
@@ -113,7 +113,7 @@ private[sbt] object ConvertResolver {
           {
             val pattern = Collections.singletonList(Resolver.resolvePattern(repo.root, Resolver.mavenStyleBasePattern))
             final class PluginCapableResolver extends IBiblioResolver with ChecksumFriendlyURLResolver with DescriptorRequired {
-              def setPatterns() {
+              def setPatterns(): Unit = {
                 // done this way for access to protected methods.
                 setArtifactPatterns(pattern)
                 setIvyPatterns(pattern)
@@ -189,18 +189,18 @@ private[sbt] object ConvertResolver {
     def hasExplicitURL(dd: DependencyDescriptor): Boolean =
       dd.getAllDependencyArtifacts.exists(_.getUrl != null)
   }
-  private def initializeMavenStyle(resolver: IBiblioResolver, name: String, root: String) {
+  private def initializeMavenStyle(resolver: IBiblioResolver, name: String, root: String): Unit = {
     resolver.setName(name)
     resolver.setM2compatible(true)
     resolver.setRoot(root)
   }
-  private def initializeSSHResolver(resolver: AbstractSshBasedResolver, repo: SshBasedRepository, settings: IvySettings) {
+  private def initializeSSHResolver(resolver: AbstractSshBasedResolver, repo: SshBasedRepository, settings: IvySettings): Unit = {
     resolver.setName(repo.name)
     resolver.setPassfile(null)
     initializePatterns(resolver, repo.patterns, settings)
     initializeConnection(resolver, repo.connection)
   }
-  private def initializeConnection(resolver: AbstractSshBasedResolver, connection: RepositoryHelpers.SshConnection) {
+  private def initializeConnection(resolver: AbstractSshBasedResolver, connection: RepositoryHelpers.SshConnection): Unit = {
     import resolver._
     import connection._
     hostname.foreach(setHost)
@@ -216,7 +216,7 @@ private[sbt] object ConvertResolver {
           setUser(user)
       }
   }
-  private def initializePatterns(resolver: AbstractPatternsBasedResolver, patterns: Patterns, settings: IvySettings) {
+  private def initializePatterns(resolver: AbstractPatternsBasedResolver, patterns: Patterns, settings: IvySettings): Unit = {
     resolver.setM2compatible(patterns.isMavenCompatible)
     resolver.setDescriptor(if (patterns.descriptorOptional) BasicResolver.DESCRIPTOR_OPTIONAL else BasicResolver.DESCRIPTOR_REQUIRED)
     resolver.setCheckconsistency(!patterns.skipConsistencyCheck)
diff --git a/ivy/src/main/scala/sbt/CustomXmlParser.scala b/ivy/src/main/scala/sbt/CustomXmlParser.scala
index c5462070c..bc8d7544b 100644
--- a/ivy/src/main/scala/sbt/CustomXmlParser.scala
+++ b/ivy/src/main/scala/sbt/CustomXmlParser.scala
@@ -21,9 +21,9 @@ private[sbt] object CustomXmlParser extends XmlModuleDescriptorParser {
         super.setResource(new URLResource(url))
         super.setInput(url)
       }
-    def setInput(bytes: Array[Byte]) { setInput(new ByteArrayInputStream(bytes)) }
+    def setInput(bytes: Array[Byte]): Unit = setInput(new ByteArrayInputStream(bytes))
     /** Overridden because the super implementation overwrites the module descriptor.*/
-    override def setResource(res: Resource) {}
+    override def setResource(res: Resource): Unit = ()
     override def setMd(md: DefaultModuleDescriptor) =
       {
         super.setMd(md)
@@ -32,4 +32,4 @@ private[sbt] object CustomXmlParser extends XmlModuleDescriptorParser {
     override def parseDepsConfs(confs: String, dd: DefaultDependencyDescriptor) = super.parseDepsConfs(confs, dd)
     override def getDefaultConf = defaultConfig.getOrElse(super.getDefaultConf)
   }
-}
\ No newline at end of file
+}
diff --git a/ivy/src/main/scala/sbt/Ivy.scala b/ivy/src/main/scala/sbt/Ivy.scala
index 7e4cf3792..e9ac5a23d 100644
--- a/ivy/src/main/scala/sbt/Ivy.scala
+++ b/ivy/src/main/scala/sbt/Ivy.scala
@@ -231,7 +231,7 @@ final class IvySbt(val configuration: IvyConfiguration) {
           addScalaToolDependencies(dmd, parser, is)
         (dmd, parser.getDefaultConf)
       }
-    private def addScalaToolDependencies(dmd: DefaultModuleDescriptor, parser: CustomXmlParser.CustomParser, is: IvyScala) {
+    private def addScalaToolDependencies(dmd: DefaultModuleDescriptor, parser: CustomXmlParser.CustomParser, is: IvyScala): Unit = {
       IvySbt.addConfigurations(dmd, Configurations.ScalaTool :: Nil)
       IvySbt.addDependencies(dmd, ScalaArtifacts.toolDependencies(is.scalaOrganization, is.scalaFullVersion), parser)
     }
@@ -257,7 +257,7 @@ private[sbt] object IvySbt {
   def defaultIvyConfiguration(project: File) = new File(project, DefaultIvyConfigFilename)
   def defaultPOM(project: File) = new File(project, DefaultMavenFilename)
 
-  def loadURI(is: IvySettings, uri: URI) {
+  def loadURI(is: IvySettings, uri: URI): Unit = {
     if (uri.getScheme == "file")
       is.load(new File(uri)) // IVY-1114
     else
@@ -268,7 +268,7 @@ private[sbt] object IvySbt {
    * Sets the resolvers for 'settings' to 'resolvers'.  This is done by creating a new chain and making it the default.
    * 'other' is for resolvers that should be in a different chain.  These are typically used for publishing or other actions.
    */
-  private def setResolvers(settings: IvySettings, resolvers: Seq[Resolver], other: Seq[Resolver], localOnly: Boolean, updateOptions: UpdateOptions, log: Logger) {
+  private def setResolvers(settings: IvySettings, resolvers: Seq[Resolver], other: Seq[Resolver], localOnly: Boolean, updateOptions: UpdateOptions, log: Logger): Unit = {
     def makeChain(label: String, name: String, rs: Seq[Resolver]) = {
       log.debug(label + " repositories:")
       val chain = resolverChain(name, rs, localOnly, settings, updateOptions, log)
@@ -304,7 +304,7 @@ private[sbt] object IvySbt {
 
     }
   }
-  def addResolvers(resolvers: Seq[Resolver], settings: IvySettings, log: Logger) {
+  def addResolvers(resolvers: Seq[Resolver], settings: IvySettings, log: Logger): Unit = {
     for (r <- resolvers) {
       log.debug("\t" + r)
       settings.addResolver(ConvertResolver(r, settings, log))
@@ -320,7 +320,7 @@ private[sbt] object IvySbt {
       import collection.JavaConversions._
       artifact.getQualifiedExtraAttributes.keys.exists(_.asInstanceOf[String] startsWith "m:")
     }
-  private def setModuleConfigurations(settings: IvySettings, moduleConfigurations: Seq[ModuleConfiguration], log: Logger) {
+  private def setModuleConfigurations(settings: IvySettings, moduleConfigurations: Seq[ModuleConfiguration], log: Logger): Unit = {
     val existing = settings.getResolverNames
     for (moduleConf <- moduleConfigurations) {
       import moduleConf._
@@ -332,11 +332,11 @@ private[sbt] object IvySbt {
       settings.addModuleConfiguration(attributes, settings.getMatcher(EXACT_OR_REGEXP), resolver.name, null, null, null)
     }
   }
-  private def configureCache(settings: IvySettings, localOnly: Boolean, resCacheDir: Option[File]) {
+  private def configureCache(settings: IvySettings, localOnly: Boolean, resCacheDir: Option[File]): Unit = {
     configureResolutionCache(settings, localOnly, resCacheDir)
     configureRepositoryCache(settings, localOnly)
   }
-  private[this] def configureResolutionCache(settings: IvySettings, localOnly: Boolean, resCacheDir: Option[File]) {
+  private[this] def configureResolutionCache(settings: IvySettings, localOnly: Boolean, resCacheDir: Option[File]): Unit = {
     val base = resCacheDir getOrElse settings.getDefaultResolutionCacheBasedir
     settings.setResolutionCacheManager(new ResolutionCache(base, settings))
   }
@@ -385,7 +385,7 @@ private[sbt] object IvySbt {
         case _                   => false
       }
       // ignore the original resolver wherever possible to avoid issues like #704
-      override def saveResolvers(descriptor: ModuleDescriptor, metadataResolverName: String, artifactResolverName: String) {}
+      override def saveResolvers(descriptor: ModuleDescriptor, metadataResolverName: String, artifactResolverName: String): Unit = ()
     }
     manager.setArtifactPattern(PluginPattern + manager.getArtifactPattern)
     manager.setDataFilePattern(PluginPattern + manager.getDataFilePattern)
@@ -411,12 +411,12 @@ private[sbt] object IvySbt {
     dmd.addExtraAttributeNamespace("e", "http://ant.apache.org/ivy/extra")
 
   /** Adds the ivy.xml main artifact. */
-  private def addMainArtifact(moduleID: DefaultModuleDescriptor) {
+  private def addMainArtifact(moduleID: DefaultModuleDescriptor): Unit = {
     val artifact = DefaultArtifact.newIvyArtifact(moduleID.getResolvedModuleRevisionId, moduleID.getPublicationDate)
     moduleID.setModuleArtifact(artifact)
     moduleID.check()
   }
-  private def setConflictManager(moduleID: DefaultModuleDescriptor, conflict: ConflictManager, is: IvySettings) {
+  private def setConflictManager(moduleID: DefaultModuleDescriptor, conflict: ConflictManager, is: IvySettings): Unit = {
     val mid = ModuleId.newInstance(conflict.organization, conflict.module)
     val matcher = is.getMatcher(PatternMatcher.EXACT_OR_REGEXP)
     val manager = is.getConflictManager(conflict.name)
@@ -555,7 +555,7 @@ private[sbt] object IvySbt {
     }
 
   /** This method is used to add inline dependencies to the provided module. */
-  def addDependencies(moduleID: DefaultModuleDescriptor, dependencies: Seq[ModuleID], parser: CustomXmlParser.CustomParser) {
+  def addDependencies(moduleID: DefaultModuleDescriptor, dependencies: Seq[ModuleID], parser: CustomXmlParser.CustomParser): Unit = {
     val converted = dependencies map { dependency => convertDependency(moduleID, dependency, parser) }
     val unique = if (hasDuplicateDependencies(converted)) mergeDuplicateDefinitions(converted) else converted
     unique foreach moduleID.addDependency
@@ -579,7 +579,7 @@ private[sbt] object IvySbt {
    */
   def mergeDuplicateDefinitions(dependencies: Seq[DependencyDescriptor]): Seq[DependencyDescriptor] =
     {
-      // need to preserve basic order of dependencies: can't use dependencies.groupBy 
+      // need to preserve basic order of dependencies: can't use dependencies.groupBy
       val deps = new java.util.LinkedHashMap[ModuleRevisionId, List[DependencyDescriptor]]
       for (dd <- dependencies) {
         val id = dd.getDependencyRevisionId
diff --git a/ivy/src/main/scala/sbt/IvyActions.scala b/ivy/src/main/scala/sbt/IvyActions.scala
index ef2db547e..33436452c 100644
--- a/ivy/src/main/scala/sbt/IvyActions.scala
+++ b/ivy/src/main/scala/sbt/IvyActions.scala
@@ -61,7 +61,7 @@ object UpdateLogging extends Enumeration {
 
 object IvyActions {
   /** Installs the dependencies of the given 'module' from the resolver named 'from' to the resolver named 'to'.*/
-  def install(module: IvySbt#Module, from: String, to: String, log: Logger) {
+  def install(module: IvySbt#Module, from: String, to: String, log: Logger): Unit = {
     module.withModule(log) { (ivy, md, default) =>
       for (dependency <- md.getDependencies) {
         log.info("Installing " + dependency)
@@ -89,7 +89,7 @@ object IvyActions {
     }
 
   /** Creates a Maven pom from the given Ivy configuration*/
-  def makePom(module: IvySbt#Module, configuration: MakePomConfiguration, log: Logger) {
+  def makePom(module: IvySbt#Module, configuration: MakePomConfiguration, log: Logger): Unit = {
     import configuration.{ allRepositories, moduleInfo, configurations, extra, file, filterRepositories, process, includeTypes }
     module.withModule(log) { (ivy, md, default) =>
       (new MakePom(log)).write(ivy, md, moduleInfo, configurations, includeTypes, extra, process, filterRepositories, allRepositories, file)
@@ -112,7 +112,7 @@ object IvyActions {
   def deliveredFile(ivy: Ivy, pattern: String, md: ModuleDescriptor): File =
     ivy.getSettings.resolveFile(IvyPatternHelper.substitute(pattern, md.getResolvedModuleRevisionId))
 
-  def publish(module: IvySbt#Module, configuration: PublishConfiguration, log: Logger) {
+  def publish(module: IvySbt#Module, configuration: PublishConfiguration, log: Logger): Unit = {
     import configuration._
     module.withModule(log) {
       case (ivy, md, default) =>
@@ -368,7 +368,7 @@ object IvyActions {
         }
       }
     }
-  private[this] def checkFilesPresent(artifacts: Seq[(IArtifact, File)]) {
+  private[this] def checkFilesPresent(artifacts: Seq[(IArtifact, File)]): Unit = {
     val missing = artifacts filter { case (a, file) => !file.exists }
     if (missing.nonEmpty)
       sys.error("Missing files for publishing:\n\t" + missing.map(_._2.getAbsolutePath).mkString("\n\t"))
diff --git a/ivy/src/main/scala/sbt/IvyCache.scala b/ivy/src/main/scala/sbt/IvyCache.scala
index 51e02b60c..ce2ddd9f2 100644
--- a/ivy/src/main/scala/sbt/IvyCache.scala
+++ b/ivy/src/main/scala/sbt/IvyCache.scala
@@ -28,7 +28,7 @@ private object NotInCache {
 class IvyCache(val ivyHome: Option[File]) {
   def lockFile = new File(ivyHome getOrElse Path.userHome, ".sbt.cache.lock")
   /** Caches the given 'file' with the given ID.  It may be retrieved or cleared using this ID.*/
-  def cacheJar(moduleID: ModuleID, file: File, lock: Option[xsbti.GlobalLock], log: Logger) {
+  def cacheJar(moduleID: ModuleID, file: File, lock: Option[xsbti.GlobalLock], log: Logger): Unit = {
     val artifact = defaultArtifact(moduleID)
     val resolved = new ResolvedResource(new FileResource(new IvyFileRepository, file), moduleID.revision)
     withDefaultCache(lock, log) { cache =>
@@ -37,7 +37,7 @@ class IvyCache(val ivyHome: Option[File]) {
     }
   }
   /** Clears the cache of the jar for the given ID.*/
-  def clearCachedJar(id: ModuleID, lock: Option[xsbti.GlobalLock], log: Logger) {
+  def clearCachedJar(id: ModuleID, lock: Option[xsbti.GlobalLock], log: Logger): Unit = {
     try { withCachedJar(id, lock, log)(_.delete) }
     catch { case e: Exception => log.debug("Error cleaning cached jar: " + e.toString) }
   }
@@ -87,11 +87,11 @@ class IvyCache(val ivyHome: Option[File]) {
 }
 /** Required by Ivy for copying to the cache.*/
 private class FileDownloader extends ResourceDownloader with NotNull {
-  def download(artifact: IvyArtifact, resource: Resource, dest: File) {
+  def download(artifact: IvyArtifact, resource: Resource, dest: File): Unit = {
     if (dest.exists()) dest.delete()
     val part = new File(dest.getAbsolutePath + ".part")
     FileUtil.copy(resource.openStream, part, null)
     if (!part.renameTo(dest))
       sys.error("Could not move temporary file " + part + " to final location " + dest)
   }
-}
\ No newline at end of file
+}
diff --git a/ivy/src/main/scala/sbt/IvyLogger.scala b/ivy/src/main/scala/sbt/IvyLogger.scala
index 42131a174..94268672e 100644
--- a/ivy/src/main/scala/sbt/IvyLogger.scala
+++ b/ivy/src/main/scala/sbt/IvyLogger.scala
@@ -7,8 +7,8 @@ import org.apache.ivy.util.{ Message, MessageLogger, MessageLoggerEngine }
 
 /** Interface to Ivy logging. */
 private final class IvyLoggerInterface(logger: Logger) extends MessageLogger {
-  def rawlog(msg: String, level: Int) = log(msg, level)
-  def log(msg: String, level: Int) {
+  def rawlog(msg: String, level: Int): Unit = log(msg, level)
+  def log(msg: String, level: Int): Unit = {
     import Message.{ MSG_DEBUG, MSG_VERBOSE, MSG_INFO, MSG_WARN, MSG_ERR }
     level match {
       case MSG_DEBUG   => debug(msg)
@@ -20,32 +20,32 @@ private final class IvyLoggerInterface(logger: Logger) extends MessageLogger {
   }
   //DEBUG level messages are very verbose and rarely useful to users.
   // TODO: provide access to this information some other way
-  def debug(msg: String) {}
-  def verbose(msg: String) = logger.verbose(msg)
-  def deprecated(msg: String) = warn(msg)
-  def info(msg: String) = logger.info(msg)
-  def rawinfo(msg: String) = info(msg)
-  def warn(msg: String) = logger.warn(msg)
-  def error(msg: String) = if (SbtIvyLogger.acceptError(msg)) logger.error(msg)
+  def debug(msg: String): Unit = ()
+  def verbose(msg: String): Unit = logger.verbose(msg)
+  def deprecated(msg: String): Unit = warn(msg)
+  def info(msg: String): Unit = logger.info(msg)
+  def rawinfo(msg: String): Unit = info(msg)
+  def warn(msg: String): Unit = logger.warn(msg)
+  def error(msg: String): Unit = if (SbtIvyLogger.acceptError(msg)) logger.error(msg)
 
   private def emptyList = java.util.Collections.emptyList[String]
   def getProblems = emptyList
   def getWarns = emptyList
   def getErrors = emptyList
 
-  def clearProblems = ()
-  def sumupProblems = clearProblems()
-  def progress = ()
-  def endProgress = ()
+  def clearProblems(): Unit = ()
+  def sumupProblems(): Unit = clearProblems()
+  def progress(): Unit = ()
+  def endProgress(): Unit = ()
 
-  def endProgress(msg: String) = info(msg)
+  def endProgress(msg: String): Unit = info(msg)
   def isShowProgress = false
-  def setShowProgress(progress: Boolean) {}
+  def setShowProgress(progress: Boolean): Unit = ()
 }
 private final class SbtMessageLoggerEngine extends MessageLoggerEngine {
   /** This is a hack to filter error messages about 'unknown resolver ...'. */
-  override def error(msg: String) = if (SbtIvyLogger.acceptError(msg)) super.error(msg)
-  override def sumupProblems = clearProblems()
+  override def error(msg: String): Unit = if (SbtIvyLogger.acceptError(msg)) super.error(msg)
+  override def sumupProblems(): Unit = clearProblems()
 }
 private object SbtIvyLogger {
   val UnknownResolver = "unknown resolver"
diff --git a/ivy/src/main/scala/sbt/IvyScala.scala b/ivy/src/main/scala/sbt/IvyScala.scala
index d2697e308..2614df994 100644
--- a/ivy/src/main/scala/sbt/IvyScala.scala
+++ b/ivy/src/main/scala/sbt/IvyScala.scala
@@ -37,7 +37,7 @@ final case class IvyScala(scalaFullVersion: String, scalaBinaryVersion: String,
 
 private object IvyScala {
   /** Performs checks/adds filters on Scala dependencies (if enabled in IvyScala). */
-  def checkModule(module: DefaultModuleDescriptor, conf: String, log: Logger)(check: IvyScala) {
+  def checkModule(module: DefaultModuleDescriptor, conf: String, log: Logger)(check: IvyScala): Unit = {
     if (check.checkExplicit)
       checkDependencies(module, check.scalaBinaryVersion, check.configurations, log)
     if (check.filterImplicit)
@@ -45,12 +45,12 @@ private object IvyScala {
     if (check.overrideScalaVersion)
       overrideScalaVersion(module, check.scalaFullVersion)
   }
-  def overrideScalaVersion(module: DefaultModuleDescriptor, version: String) {
+  def overrideScalaVersion(module: DefaultModuleDescriptor, version: String): Unit = {
     overrideVersion(module, Organization, LibraryID, version)
     overrideVersion(module, Organization, CompilerID, version)
     overrideVersion(module, Organization, ReflectID, version)
   }
-  def overrideVersion(module: DefaultModuleDescriptor, org: String, name: String, version: String) {
+  def overrideVersion(module: DefaultModuleDescriptor, org: String, name: String, version: String): Unit = {
     val id = new ModuleId(org, name)
     val over = new OverrideDependencyDescriptorMediator(null, version)
     module.addDependencyDescriptorMediator(id, ExactPatternMatcher.INSTANCE, over)
@@ -60,7 +60,7 @@ private object IvyScala {
    * Checks the immediate dependencies of module for dependencies on scala jars and verifies that the version on the
    * dependencies matches scalaVersion.
    */
-  private def checkDependencies(module: ModuleDescriptor, scalaBinaryVersion: String, configurations: Iterable[Configuration], log: Logger) {
+  private def checkDependencies(module: ModuleDescriptor, scalaBinaryVersion: String, configurations: Iterable[Configuration], log: Logger): Unit = {
     val configSet = if (configurations.isEmpty) (c: String) => true else configurationSet(configurations)
     def binaryScalaWarning(dep: DependencyDescriptor): Option[String] =
       {
@@ -88,7 +88,7 @@ private object IvyScala {
    * done because these jars are provided by the ScalaInstance of the project.  The version of Scala to use
    * is done by setting scalaVersion in the project definition.
    */
-  private def excludeScalaJars(module: DefaultModuleDescriptor, configurations: Iterable[Configuration]) {
+  private def excludeScalaJars(module: DefaultModuleDescriptor, configurations: Iterable[Configuration]): Unit = {
     val configurationNames =
       {
         val names = module.getConfigurationsNames
diff --git a/ivy/src/main/scala/sbt/MakePom.scala b/ivy/src/main/scala/sbt/MakePom.scala
index 81121bf7f..e2018612f 100644
--- a/ivy/src/main/scala/sbt/MakePom.scala
+++ b/ivy/src/main/scala/sbt/MakePom.scala
@@ -83,9 +83,8 @@ class MakePom(val log: Logger) {
     write(process(toPom(ivy, module, moduleInfo, configurations, includeTypes, extra, filterRepositories, allRepositories)), output)
   // use \n as newline because toString uses PrettyPrinter, which hard codes line endings to be \n
   def write(node: XNode, output: File): Unit = write(toString(node), output, "\n")
-  def write(xmlString: String, output: File, newline: String) {
+  def write(xmlString: String, output: File, newline: String): Unit =
     IO.write(output, "<?xml version='1.0' encoding='" + IO.utf8.name + "'?>" + newline + xmlString)
-  }
 
   def toString(node: XNode): String = new PrettyPrinter(1000, 4).format(node)
   @deprecated("Use `toPom(Ivy, ModuleDescriptor, ModuleInfo, Option[Iterable[Configuration]], Set[String], NodeSeq, MavenRepository => Boolean, Boolean)` instead", "0.11.2")
diff --git a/ivy/src/main/scala/sbt/ProjectResolver.scala b/ivy/src/main/scala/sbt/ProjectResolver.scala
index a51e0abb8..61c811e7b 100644
--- a/ivy/src/main/scala/sbt/ProjectResolver.scala
+++ b/ivy/src/main/scala/sbt/ProjectResolver.scala
@@ -70,12 +70,12 @@ class ProjectResolver(name: String, map: Map[ModuleRevisionId, ModuleDescriptor]
 
   // doesn't support publishing
   def publish(artifact: IArtifact, src: File, overwrite: Boolean) = sys.error("Publish not supported by ProjectResolver")
-  def beginPublishTransaction(module: ModuleRevisionId, overwrite: Boolean) {}
-  def abortPublishTransaction() {}
-  def commitPublishTransaction() {}
+  def beginPublishTransaction(module: ModuleRevisionId, overwrite: Boolean): Unit = ()
+  def abortPublishTransaction(): Unit = ()
+  def commitPublishTransaction(): Unit = ()
 
-  def reportFailure() {}
-  def reportFailure(art: IArtifact) {}
+  def reportFailure(): Unit = ()
+  def reportFailure(art: IArtifact): Unit = ()
 
   def listOrganisations() = new Array[OrganisationEntry](0)
   def listModules(org: OrganisationEntry) = new Array[ModuleEntry](0)
@@ -85,8 +85,8 @@ class ProjectResolver(name: String, map: Map[ModuleRevisionId, ModuleDescriptor]
 
   private[this] var settings: Option[ResolverSettings] = None
 
-  def dumpSettings() {}
-  def setSettings(settings: ResolverSettings) { this.settings = Some(settings) }
+  def dumpSettings(): Unit = ()
+  def setSettings(settings: ResolverSettings): Unit = { this.settings = Some(settings) }
   def getRepositoryCacheManager = settings match { case Some(s) => s.getDefaultRepositoryCacheManager; case None => sys.error("No settings defined for ProjectResolver") }
 }
 
diff --git a/ivy/src/main/scala/sbt/ResolutionCache.scala b/ivy/src/main/scala/sbt/ResolutionCache.scala
index 0fd7a0a06..a68c52417 100644
--- a/ivy/src/main/scala/sbt/ResolutionCache.scala
+++ b/ivy/src/main/scala/sbt/ResolutionCache.scala
@@ -28,7 +28,7 @@ private[sbt] final class ResolutionCache(base: File, settings: IvySettings) exte
   private[this] val reportBase: File = new File(base, ReportDirectory)
 
   def getResolutionCacheRoot: File = base
-  def clean() { IO.delete(base) }
+  def clean(): Unit = IO.delete(base)
   override def toString = Name
 
   def getResolvedIvyFileInCache(mrid: ModuleRevisionId): File =
@@ -66,7 +66,7 @@ private[sbt] object ResolutionCache {
    * Removes cached files from the resolution cache for the module with ID `mrid`
    * and the resolveId (as set on `ResolveOptions`).
    */
-  private[sbt] def cleanModule(mrid: ModuleRevisionId, resolveId: String, manager: ResolutionCacheManager) {
+  private[sbt] def cleanModule(mrid: ModuleRevisionId, resolveId: String, manager: ResolutionCacheManager): Unit = {
     val files =
       Option(manager.getResolvedIvyFileInCache(mrid)).toList :::
         Option(manager.getResolvedIvyPropertiesInCache(mrid)).toList :::
@@ -87,4 +87,4 @@ private[sbt] object ResolutionCache {
 
   // use sbt-specific extra attributes so that resolved xml files do not get overwritten when using different Scala/sbt versions
   private val ResolvedPattern = "[organisation]/[module]/" + Resolver.PluginPattern + "[revision]/[artifact].[ext]"
-}
\ No newline at end of file
+}
diff --git a/ivy/src/main/scala/sbt/StringUtilities.scala b/ivy/src/main/scala/sbt/StringUtilities.scala
index fc8327304..40018250e 100644
--- a/ivy/src/main/scala/sbt/StringUtilities.scala
+++ b/ivy/src/main/scala/sbt/StringUtilities.scala
@@ -8,8 +8,6 @@ import java.util.Locale
 object StringUtilities {
   @deprecated("Different use cases require different normalization.  Use Project.normalizeModuleID or normalizeProjectID instead.", "0.13.0")
   def normalize(s: String) = s.toLowerCase(Locale.ENGLISH).replaceAll("""\W+""", "-")
-  def nonEmpty(s: String, label: String) {
-    require(s.trim.length > 0, label + " cannot be empty.")
-  }
+  def nonEmpty(s: String, label: String): Unit = require(s.trim.length > 0, label + " cannot be empty.")
   def appendable(s: String) = if (s.isEmpty) "" else "_" + s
 }
diff --git a/ivy/src/main/scala/sbt/ivyint/ErrorMessageAuthenticator.scala b/ivy/src/main/scala/sbt/ivyint/ErrorMessageAuthenticator.scala
index bb5996834..5d067d313 100644
--- a/ivy/src/main/scala/sbt/ivyint/ErrorMessageAuthenticator.scala
+++ b/ivy/src/main/scala/sbt/ivyint/ErrorMessageAuthenticator.scala
@@ -54,7 +54,7 @@ object ErrorMessageAuthenticator {
   }
 
   /** Installs the error message authenticator so we have nicer error messages when using java's URL for downloading. */
-  def install() {
+  def install(): Unit = {
     // Actually installs the error message authenticator.
     def doInstall(original: Option[Authenticator]): Unit =
       try Authenticator.setDefault(new ErrorMessageAuthenticator(original))
@@ -126,4 +126,4 @@ private[sbt] final class ErrorMessageAuthenticator(original: Option[Authenticato
   private def isProxyAuthentication: Boolean =
     getRequestorType == Authenticator.RequestorType.PROXY
 
-}
\ No newline at end of file
+}