diff --git a/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp b/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp
index f9de54a173d1..097a351e30b1 100644
--- a/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp
+++ b/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp
@@ -615,9 +615,13 @@ CallGraphNode *ArgPromotion::DoPromotion(Function *F,
 
   // Patch the pointer to LLVM function in debug info descriptor.
   auto DI = FunctionDIs.find(F);
-  if (DI != FunctionDIs.end())
-    DI->second.replaceFunction(NF);
-  
+  if (DI != FunctionDIs.end()) {
+    DISubprogram SP = DI->second;
+    SP.replaceFunction(NF);
+    FunctionDIs.erase(DI);
+    FunctionDIs[NF] = SP;
+  }
+
   DEBUG(dbgs() << "ARG PROMOTION:  Promoting to:" << *NF << "\n"
         << "From: " << *F);
   
diff --git a/llvm/test/Transforms/ArgumentPromotion/dbg.ll b/llvm/test/Transforms/ArgumentPromotion/dbg.ll
index fd0b1e996eb5..1b69e5bbf3cb 100644
--- a/llvm/test/Transforms/ArgumentPromotion/dbg.ll
+++ b/llvm/test/Transforms/ArgumentPromotion/dbg.ll
@@ -4,14 +4,15 @@
 
 declare void @sink(i32)
 
-define internal void @test(i32* %X) {
-  %1 = load i32* %X, align 8
-  call void @sink(i32 %1)
+define internal void @test(i32** %X) {
+  %1 = load i32** %X, align 8
+  %2 = load i32* %1, align 8
+  call void @sink(i32 %2)
   ret void
 }
 
-define void @caller(i32* %Y) {
-  call void @test(i32* %Y)
+define void @caller(i32** %Y) {
+  call void @test(i32** %Y)
   ret void
 }
 
@@ -20,6 +21,6 @@ define void @caller(i32* %Y) {
 
 !0 = metadata !{i32 2, metadata !"Debug Info Version", i32 1}
 !1 = metadata !{i32 8, i32 0, metadata !2, null}
-!2 = metadata !{i32 786478, null, null, metadata !"test", metadata !"test", metadata !"", i32 3, null, i1 true, i1 true, i32 0, i32 0, null, i32 256, i1 false, void (i32*)* @test, null, null, null, i32 3}
+!2 = metadata !{i32 786478, null, null, metadata !"test", metadata !"test", metadata !"", i32 3, null, i1 true, i1 true, i32 0, i32 0, null, i32 256, i1 false, void (i32**)* @test, null, null, null, i32 3}
 !3 = metadata !{i32 786449, null, i32 4, metadata !"clang version 3.5.0 ", i1 false, metadata !"", i32 0, null, null, metadata !4, null, null, metadata !"", i32 2} ; [ DW_TAG_compile_unit ] [/usr/local/google/home/blaikie/dev/scratch/pr20038/reduce/<stdin>] [DW_LANG_C_plus_plus]
 !4 = metadata !{metadata !2}