diff --git a/internal/zinc-core/src/main/scala/sbt/internal/inc/IncrementalNameHashing.scala b/internal/zinc-core/src/main/scala/sbt/internal/inc/IncrementalNameHashing.scala
index 9381ec1fb9..2cfd8ff396 100644
--- a/internal/zinc-core/src/main/scala/sbt/internal/inc/IncrementalNameHashing.scala
+++ b/internal/zinc-core/src/main/scala/sbt/internal/inc/IncrementalNameHashing.scala
@@ -44,9 +44,16 @@ private[inc] class IncrementalNameHashingCommon(
       apis: APIs
   ): Set[String] = {
     val findSubclasses = relations.inheritance.internal.reverse _
+    val invalidatedClassesAndCodefinedClasses = for {
+      cls <- invalidatedClasses.iterator
+      file <- relations.definesClass(cls).iterator
+      cls1 <- relations.classNames(file)
+    } yield cls1
+
     debug("Invalidate package objects by inheritance only...")
     val invalidatedPackageObjects =
-      transitiveDeps(invalidatedClasses, log)(findSubclasses).filter(_.endsWith(".package"))
+      transitiveDeps(invalidatedClassesAndCodefinedClasses.toSet, log)(findSubclasses)
+        .filter(_.endsWith(".package"))
     debug(s"Package object invalidations: ${invalidatedPackageObjects.mkString(", ")}")
     invalidatedPackageObjects
   }
diff --git a/zinc/src/sbt-test/source-dependencies/package-object-name-inner/A.scala b/zinc/src/sbt-test/source-dependencies/package-object-name-inner/A.scala
new file mode 100644
index 0000000000..deb2b552a6
--- /dev/null
+++ b/zinc/src/sbt-test/source-dependencies/package-object-name-inner/A.scala
@@ -0,0 +1,7 @@
+package b
+
+class A {
+  class Inner {
+    O.o
+  }
+}
diff --git a/zinc/src/sbt-test/source-dependencies/package-object-name-inner/O.scala b/zinc/src/sbt-test/source-dependencies/package-object-name-inner/O.scala
new file mode 100644
index 0000000000..89d388076e
--- /dev/null
+++ b/zinc/src/sbt-test/source-dependencies/package-object-name-inner/O.scala
@@ -0,0 +1,5 @@
+package b
+
+object O {
+  def o = ""
+}
diff --git a/zinc/src/sbt-test/source-dependencies/package-object-name-inner/b.scala b/zinc/src/sbt-test/source-dependencies/package-object-name-inner/b.scala
new file mode 100644
index 0000000000..0a6e215a52
--- /dev/null
+++ b/zinc/src/sbt-test/source-dependencies/package-object-name-inner/b.scala
@@ -0,0 +1 @@
+package object b extends A
diff --git a/zinc/src/sbt-test/source-dependencies/package-object-name-inner/changes/O1.scala b/zinc/src/sbt-test/source-dependencies/package-object-name-inner/changes/O1.scala
new file mode 100644
index 0000000000..afbcaef289
--- /dev/null
+++ b/zinc/src/sbt-test/source-dependencies/package-object-name-inner/changes/O1.scala
@@ -0,0 +1,5 @@
+package b
+
+object O {
+  def o = 42
+}
diff --git a/zinc/src/sbt-test/source-dependencies/package-object-name-inner/test b/zinc/src/sbt-test/source-dependencies/package-object-name-inner/test
new file mode 100644
index 0000000000..9379c031e7
--- /dev/null
+++ b/zinc/src/sbt-test/source-dependencies/package-object-name-inner/test
@@ -0,0 +1,4 @@
+> compile
+$ copy-file changes/O1.scala O.scala
+> compile
+> checkIterations 3