diff --git a/Source/cmGeneratorTarget.cxx b/Source/cmGeneratorTarget.cxx
index 171c3ed395d80576de6f72c94fa4d2ac2c8e2f64..cde91c90ce76aceb1eb564b4b371fcd3b9236bf3 100644
--- a/Source/cmGeneratorTarget.cxx
+++ b/Source/cmGeneratorTarget.cxx
@@ -652,6 +652,7 @@ const char* cmGeneratorTarget::GetFileSuffixInternal(
 
 void cmGeneratorTarget::ClearSourcesCache()
 {
+  this->AllConfigSources.clear();
   this->KindedSourcesMap.clear();
   this->LinkImplementationLanguageIsContextDependent = true;
   this->Objects.clear();