diff --git a/llvm/include/llvm/Analysis/CallGraph.h b/llvm/include/llvm/Analysis/CallGraph.h
--- a/llvm/include/llvm/Analysis/CallGraph.h
+++ b/llvm/include/llvm/Analysis/CallGraph.h
@@ -138,6 +138,10 @@
     return CallsExternalNode.get();
   }
 
+  /// Old node has been deleted, and New is to be used in its place, update the
+  /// ExternalCallingNode.
+  void ReplaceExternalCallEdge(CallGraphNode *Old, CallGraphNode *New);
+
   //===---------------------------------------------------------------------
   // Functions to keep a call graph up to date with a function that has been
   // modified.
diff --git a/llvm/lib/Analysis/CallGraph.cpp b/llvm/lib/Analysis/CallGraph.cpp
--- a/llvm/lib/Analysis/CallGraph.cpp
+++ b/llvm/lib/Analysis/CallGraph.cpp
@@ -127,6 +127,16 @@
 LLVM_DUMP_METHOD void CallGraph::dump() const { print(dbgs()); }
 #endif
 
+void CallGraph::ReplaceExternalCallEdge(CallGraphNode *Old,
+                                        CallGraphNode *New) {
+  for (auto &CR : ExternalCallingNode->CalledFunctions)
+    if (CR.second == Old) {
+      CR.second->DropRef();
+      CR.second = New;
+      CR.second->AddRef();
+    }
+}
+
 // removeFunctionFromModule - Unlink the function from this module, returning
 // it.  Because this removes the function from the module, the call graph node
 // is destroyed.  This is only valid if the function does not call any other
diff --git a/llvm/lib/Transforms/Utils/CallGraphUpdater.cpp b/llvm/lib/Transforms/Utils/CallGraphUpdater.cpp
--- a/llvm/lib/Transforms/Utils/CallGraphUpdater.cpp
+++ b/llvm/lib/Transforms/Utils/CallGraphUpdater.cpp
@@ -114,6 +114,7 @@
     CallGraphNode *OldCGN = (*CG)[&OldFn];
     CallGraphNode *NewCGN = CG->getOrInsertFunction(&NewFn);
     NewCGN->stealCalledFunctionsFrom(OldCGN);
+    CG->ReplaceExternalCallEdge(OldCGN, NewCGN);
 
     // And update the SCC we're iterating as well.
     CGSCC->ReplaceNode(OldCGN, NewCGN);