diff --git a/clang/lib/CrossTU/CrossTranslationUnit.cpp b/clang/lib/CrossTU/CrossTranslationUnit.cpp
--- a/clang/lib/CrossTU/CrossTranslationUnit.cpp
+++ b/clang/lib/CrossTU/CrossTranslationUnit.cpp
@@ -12,6 +12,7 @@
 #include "clang/CrossTU/CrossTranslationUnit.h"
 #include "clang/AST/ASTImporter.h"
 #include "clang/AST/Decl.h"
+#include "clang/AST/ParentMapContext.h"
 #include "clang/Basic/TargetInfo.h"
 #include "clang/CrossTU/CrossTUDiagnostic.h"
 #include "clang/Frontend/ASTUnit.h"
@@ -718,6 +719,9 @@
   assert(hasBodyOrInit(ToDecl) && "Imported Decl should have body or init.");
   ++NumGetCTUSuccess;
 
+  // Parent map is invalidated after changing the AST.
+  ToDecl->getASTContext().getParentMapContext().clear();
+
   return ToDecl;
 }
 
diff --git a/clang/unittests/CrossTU/CrossTranslationUnitTest.cpp b/clang/unittests/CrossTU/CrossTranslationUnitTest.cpp
--- a/clang/unittests/CrossTU/CrossTranslationUnitTest.cpp
+++ b/clang/unittests/CrossTU/CrossTranslationUnitTest.cpp
@@ -8,6 +8,7 @@
 
 #include "clang/CrossTU/CrossTranslationUnit.h"
 #include "clang/AST/ASTConsumer.h"
+#include "clang/AST/ParentMapContext.h"
 #include "clang/Frontend/CompilerInstance.h"
 #include "clang/Frontend/FrontendAction.h"
 #include "clang/Tooling/Tooling.h"
@@ -44,6 +45,10 @@
     assert(FD && FD->getName() == "f");
     bool OrigFDHasBody = FD->hasBody();
 
+    const DynTypedNodeList ParentsBeforeImport =
+        Ctx.getParentMapContext().getParents<Decl>(*FD);
+    ASSERT_FALSE(ParentsBeforeImport.empty());
+
     // Prepare the index file and the AST file.
     int ASTFD;
     llvm::SmallString<256> ASTFileName;
@@ -105,10 +110,29 @@
             EXPECT_EQ(OrigSLoc, FDWithDefinition->getLocation());
           }
         }
+
+        // Check parent map.
+        const DynTypedNodeList ParentsAfterImport =
+            Ctx.getParentMapContext().getParents<Decl>(*FD);
+        const DynTypedNodeList ParentsOfImported =
+            Ctx.getParentMapContext().getParents<Decl>(*NewFD);
+        EXPECT_TRUE(
+            checkParentListsEq(ParentsBeforeImport, ParentsAfterImport));
+        EXPECT_FALSE(ParentsOfImported.empty());
       }
     }
   }
 
+  static bool checkParentListsEq(const DynTypedNodeList &L1,
+                                 const DynTypedNodeList &L2) {
+    if (L1.size() != L2.size())
+      return false;
+    for (unsigned int I = 0; I < L1.size(); ++I)
+      if (L1[I] != L2[I])
+        return false;
+    return true;
+  }
+
 private:
   CrossTranslationUnitContext CTU;
   bool *Success;