diff --git a/main/src/main/scala/sbt/Defaults.scala b/main/src/main/scala/sbt/Defaults.scala
index 03212aa94..072a7595d 100755
--- a/main/src/main/scala/sbt/Defaults.scala
+++ b/main/src/main/scala/sbt/Defaults.scala
@@ -371,13 +371,16 @@ object Defaults extends BuildCommon {
       }).value
   )
 
-  def paths = Seq(
+  // Appended to JvmPlugin.projectSettings
+  def paths: Seq[Setting[_]] = Seq(
     baseDirectory := thisProject.value.base,
     target := baseDirectory.value / "target",
     historyPath := (historyPath or target(t => Option(t / ".history"))).value,
     sourceDirectory := baseDirectory.value / "src",
     sourceManaged := crossTarget.value / "src_managed",
-    resourceManaged := crossTarget.value / "resource_managed"
+    resourceManaged := crossTarget.value / "resource_managed",
+    // Adds subproject build.sbt files to the global list of build files to monitor
+    Scope.Global / checkBuildSources / fileInputs += baseDirectory.value.toGlob / "*.sbt"
   )
 
   lazy val configPaths = sourceConfigPaths ++ resourceConfigPaths ++ outputConfigPaths
diff --git a/sbt/src/sbt-test/nio/reload/build.sbt b/sbt/src/sbt-test/nio/reload/build.sbt
index c143ba056..c5e320e75 100644
--- a/sbt/src/sbt-test/nio/reload/build.sbt
+++ b/sbt/src/sbt-test/nio/reload/build.sbt
@@ -11,3 +11,5 @@ exists := {
 }
 
 Global / onChangedBuildSource := ReloadOnSourceChanges
+
+val sub = project
diff --git a/sbt/src/sbt-test/nio/reload/changes/broken.sbt b/sbt/src/sbt-test/nio/reload/changes/broken.sbt
index 57e15cd57..5210c3db2 100644
--- a/sbt/src/sbt-test/nio/reload/changes/broken.sbt
+++ b/sbt/src/sbt-test/nio/reload/changes/broken.sbt
@@ -8,3 +8,5 @@ exists := {
 }
 
 Global / onChangedBuildSource := ReloadOnSourceChanges
+
+val sub = project
diff --git a/sbt/src/sbt-test/nio/reload/changes/sub.sbt b/sbt/src/sbt-test/nio/reload/changes/sub.sbt
new file mode 100644
index 000000000..f0ce2b852
--- /dev/null
+++ b/sbt/src/sbt-test/nio/reload/changes/sub.sbt
@@ -0,0 +1 @@
+libraryDependencies += "org.scala-sbt" % "sbt" % "1.3.0"
\ No newline at end of file
diff --git a/sbt/src/sbt-test/nio/reload/changes/working.sbt b/sbt/src/sbt-test/nio/reload/changes/working.sbt
index c143ba056..c5e320e75 100644
--- a/sbt/src/sbt-test/nio/reload/changes/working.sbt
+++ b/sbt/src/sbt-test/nio/reload/changes/working.sbt
@@ -11,3 +11,5 @@ exists := {
 }
 
 Global / onChangedBuildSource := ReloadOnSourceChanges
+
+val sub = project
diff --git a/sbt/src/sbt-test/nio/reload/sub/build.sbt b/sbt/src/sbt-test/nio/reload/sub/build.sbt
new file mode 100644
index 000000000..e69de29bb
diff --git a/sbt/src/sbt-test/nio/reload/sub/src/main/scala/Test.scala b/sbt/src/sbt-test/nio/reload/sub/src/main/scala/Test.scala
new file mode 100644
index 000000000..405e020be
--- /dev/null
+++ b/sbt/src/sbt-test/nio/reload/sub/src/main/scala/Test.scala
@@ -0,0 +1,3 @@
+object Test {
+  val x = sbt.Keys
+}
\ No newline at end of file
diff --git a/sbt/src/sbt-test/nio/reload/test b/sbt/src/sbt-test/nio/reload/test
index abfe64f5e..81c024396 100644
--- a/sbt/src/sbt-test/nio/reload/test
+++ b/sbt/src/sbt-test/nio/reload/test
@@ -17,3 +17,9 @@ $ copy-file changes/working.sbt build.sbt
 > foo foo; reload
 
 > exists foo
+
+-> compile
+
+$ copy-file changes/sub.sbt sub/build.sbt
+
+> compile