diff --git a/lib/IR/ConstantFold.cpp b/lib/IR/ConstantFold.cpp
index 395ac3907ba..9124c111935 100644
--- a/lib/IR/ConstantFold.cpp
+++ b/lib/IR/ConstantFold.cpp
@@ -2144,9 +2144,10 @@ static Constant *ConstantFoldGetElementPtrImpl(Constant *C,
 
   // If all indices are known integers and normalized, we can do a simple
   // check for the "inbounds" property.
-  if (!Unknown && !inBounds &&
-      isa<GlobalVariable>(C) && isInBoundsIndices(Idxs))
-    return ConstantExpr::getInBoundsGetElementPtr(C, Idxs);
+  if (!Unknown && !inBounds)
+    if (auto *GV = dyn_cast<GlobalVariable>(C))
+      if (!GV->hasExternalWeakLinkage() && isInBoundsIndices(Idxs))
+        return ConstantExpr::getInBoundsGetElementPtr(C, Idxs);
 
   return nullptr;
 }
diff --git a/test/Assembler/ConstantExprNoFold.ll b/test/Assembler/ConstantExprNoFold.ll
index d21441372bf..04ad3f5b130 100644
--- a/test/Assembler/ConstantExprNoFold.ll
+++ b/test/Assembler/ConstantExprNoFold.ll
@@ -25,3 +25,15 @@ target datalayout = "p:32:32"
 
 ; CHECK: @E = global i64 addrspace(1)* addrspacecast (i64* @A to i64 addrspace(1)*)
 @E = global i64 addrspace(1)* addrspacecast(i64* @A to i64 addrspace(1)*)
+
+; Don't add an inbounds on @weak.gep, since @weak may be null.
+; CHECK: @weak.gep = global i32* getelementptr (i32* @weak, i32 1)
+@weak.gep = global i32* getelementptr (i32* @weak, i32 1)
+@weak = extern_weak global i32
+
+; Don't add an inbounds on @glob.a3, since it's not inbounds.
+; CHECK: @glob.a3 = alias getelementptr (i32* @glob.a2, i32 1)
+@glob = global i32 0
+@glob.a3 = alias getelementptr (i32* @glob.a2, i32 1)
+@glob.a2 = alias getelementptr (i32* @glob.a1, i32 1)
+@glob.a1 = alias i32* @glob