diff --git a/ivy/src/main/scala/sbt/ConflictWarning.scala b/ivy/src/main/scala/sbt/ConflictWarning.scala
index 8e0b07f7d..7498a4f13 100644
--- a/ivy/src/main/scala/sbt/ConflictWarning.scala
+++ b/ivy/src/main/scala/sbt/ConflictWarning.scala
@@ -32,7 +32,7 @@ object ConflictWarning
 			log.log(config.level, conflictMsgs.mkString(msg, "\n   ", ""))
 
 			if(config.failOnConflict)
-				error("Conflicts in " + conflicts.map(_._1).mkString(", ") )
+				sys.error("Conflicts in " + conflicts.map(_._1).mkString(", ") )
 		}
 	}
 	
@@ -51,7 +51,7 @@ object ConflictWarning
 			log.log(config.level, conflictMsgs.mkString(pre, "\n   ", ""))
 			if(config.failOnConflict) {
 				val summary = crossMismatches.map{ case ((org,raw),_) => idString(org,raw)}.mkString(", ")
-				error("Conflicting cross-version suffixes in: " + summary)
+				sys.error("Conflicting cross-version suffixes in: " + summary)
 			}
 		}
 	}
diff --git a/ivy/src/main/scala/sbt/Ivy.scala b/ivy/src/main/scala/sbt/Ivy.scala
index fee28808e..68dc273d8 100644
--- a/ivy/src/main/scala/sbt/Ivy.scala
+++ b/ivy/src/main/scala/sbt/Ivy.scala
@@ -478,10 +478,10 @@ private object IvySbt
 		{
 			def check(found: NodeSeq, expected: String, label: String) =
 				if(found.isEmpty)
-					error("Missing " + label + " in inline Ivy XML.")
+					sys.error("Missing " + label + " in inline Ivy XML.")
 				else {
 					val str = found.text
-					if(str != expected) error("Inconsistent " + label + " in inline Ivy XML.  Expected '" + expected + "', got '" + str + "'")
+					if(str != expected) sys.error("Inconsistent " + label + " in inline Ivy XML.  Expected '" + expected + "', got '" + str + "'")
 				}
 			check(info \ "@organisation", module.organization, "organisation")
 			check(info \ "@module", module.name, "name")
@@ -637,7 +637,7 @@ private object IvySbt
 		md match
 		{
 			case dmd: DefaultModuleDescriptor => dmd
-			case _ => error("Unknown ModuleDescriptor type.")
+			case _ => sys.error("Unknown ModuleDescriptor type.")
 		}
 	def getConfigurations(module: ModuleDescriptor, configurations: Option[Iterable[Configuration]]) =
 		configurations match
diff --git a/ivy/src/main/scala/sbt/IvyCache.scala b/ivy/src/main/scala/sbt/IvyCache.scala
index 1a22a9977..3ff8432f0 100644
--- a/ivy/src/main/scala/sbt/IvyCache.scala
+++ b/ivy/src/main/scala/sbt/IvyCache.scala
@@ -102,6 +102,6 @@ private class FileDownloader extends ResourceDownloader with NotNull
 		val part = new File(dest.getAbsolutePath + ".part")
 		FileUtil.copy(resource.openStream, part, null)
 		if(!part.renameTo(dest))
-			error("Could not move temporary file " + part + " to final location " + 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/MakePom.scala b/ivy/src/main/scala/sbt/MakePom.scala
index 2421c68c4..639400db0 100644
--- a/ivy/src/main/scala/sbt/MakePom.scala
+++ b/ivy/src/main/scala/sbt/MakePom.scala
@@ -275,7 +275,7 @@ class MakePom(val log: Logger)
 
 	def toID(name: String) = checkID(name.filter(isValidIDCharacter).mkString, name)
 	def isValidIDCharacter(c: Char) = c.isLetterOrDigit
-	private def checkID(id: String, name: String) = if(id.isEmpty) error("Could not convert '" + name + "' to an ID") else id
+	private def checkID(id: String, name: String) = if(id.isEmpty) sys.error("Could not convert '" + name + "' to an ID") else id
 	def mavenRepository(repo: MavenRepository): XNode =
 		mavenRepository(toID(repo.name), repo.name, repo.root)
 	def mavenRepository(id: String, name: String, root: String): XNode =
diff --git a/ivy/src/main/scala/sbt/ProjectResolver.scala b/ivy/src/main/scala/sbt/ProjectResolver.scala
index 4c2d046db..a3b31c298 100644
--- a/ivy/src/main/scala/sbt/ProjectResolver.scala
+++ b/ivy/src/main/scala/sbt/ProjectResolver.scala
@@ -22,7 +22,7 @@ package sbt
 class ProjectResolver(name: String, map: Map[ModuleRevisionId, ModuleDescriptor]) extends ResolverAdapter
 {
 	def getName = name
-	def setName(name: String) = error("Setting name not supported by ProjectResolver")
+	def setName(name: String) = sys.error("Setting name not supported by ProjectResolver")
 	override def toString = "ProjectResolver(" + name + ", mapped: " + map.keys.mkString(", ") + ")"
 
 	def getDependency(dd: DependencyDescriptor, data: ResolveData): ResolvedModuleRevision =
@@ -59,7 +59,7 @@ class ProjectResolver(name: String, map: Map[ModuleRevisionId, ModuleDescriptor]
 	}
 
 	// doesn't support publishing
-	def publish(artifact: IArtifact, src: File, overwrite: Boolean) = error("Publish not supported by ProjectResolver")
+	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() {}
@@ -77,5 +77,5 @@ class ProjectResolver(name: String, map: Map[ModuleRevisionId, ModuleDescriptor]
 
 	def dumpSettings() {}
 	def setSettings(settings: ResolverSettings) { this.settings = Some(settings) }
-	def getRepositoryCacheManager = settings match { case Some(s) => s.getDefaultRepositoryCacheManager; case None => error("No settings defined for ProjectResolver") }
+	def getRepositoryCacheManager = settings match { case Some(s) => s.getDefaultRepositoryCacheManager; case None => sys.error("No settings defined for ProjectResolver") }
 }