diff --git a/clang/lib/CodeGen/CGExprConstant.cpp b/clang/lib/CodeGen/CGExprConstant.cpp
--- a/clang/lib/CodeGen/CGExprConstant.cpp
+++ b/clang/lib/CodeGen/CGExprConstant.cpp
@@ -1127,6 +1127,13 @@
     case CK_ConstructorConversion:
       return Visit(subExpr, destType);
 
+    case CK_NullToPointer: {
+      if (llvm::Constant *C = Visit(subExpr, destType))
+        if (C->isNullValue())
+          return CGM.EmitNullConstant(destType);
+      return nullptr;
+    }
+
     case CK_IntToOCLSampler:
       llvm_unreachable("global sampler variables are not generated");
 
@@ -1183,7 +1190,6 @@
     case CK_IntegralComplexToFloatingComplex:
     case CK_PointerToIntegral:
     case CK_PointerToBoolean:
-    case CK_NullToPointer:
     case CK_IntegralCast:
     case CK_BooleanToSignedIntegral:
     case CK_IntegralToPointer: