diff --git a/compiler-rt/lib/orc/c_api.h b/compiler-rt/lib/orc/c_api.h
--- a/compiler-rt/lib/orc/c_api.h
+++ b/compiler-rt/lib/orc/c_api.h
@@ -95,6 +95,8 @@
 __orc_rt_CWrapperFunctionResultAllocate(size_t Size) {
   __orc_rt_CWrapperFunctionResult R;
   R.Size = Size;
+  // If Size is 0 ValuePtr must be 0 or it is considered an out-of-band error.
+  R.Data.ValuePtr = 0;
   if (Size > sizeof(R.Data.Value))
     R.Data.ValuePtr = (char *)malloc(Size);
   return R;
diff --git a/compiler-rt/lib/orc/unittests/c_api_test.cpp b/compiler-rt/lib/orc/unittests/c_api_test.cpp
--- a/compiler-rt/lib/orc/unittests/c_api_test.cpp
+++ b/compiler-rt/lib/orc/unittests/c_api_test.cpp
@@ -30,8 +30,8 @@
 TEST(CAPITest, CWrapperFunctionResultAllocSmall) {
   constexpr size_t SmallAllocSize = sizeof(const char *);
 
-  __orc_rt_CWrapperFunctionResult R;
-  char *DataPtr = __orc_rt_CWrapperFunctionResultAllocate(&R, SmallAllocSize);
+  auto R = __orc_rt_CWrapperFunctionResultAllocate(SmallAllocSize);
+  char *DataPtr = __orc_rt_CWrapperFunctionResultData(&R);
 
   for (size_t I = 0; I != SmallAllocSize; ++I)
     DataPtr[I] = 0x55 + I;
@@ -60,8 +60,8 @@
 TEST(CAPITest, CWrapperFunctionResultAllocLarge) {
   constexpr size_t LargeAllocSize = sizeof(const char *) + 1;
 
-  __orc_rt_CWrapperFunctionResult R;
-  char *DataPtr = __orc_rt_CWrapperFunctionResultAllocate(&R, LargeAllocSize);
+  auto R = __orc_rt_CWrapperFunctionResultAllocate(LargeAllocSize);
+  char *DataPtr = __orc_rt_CWrapperFunctionResultData(&R);
 
   for (size_t I = 0; I != LargeAllocSize; ++I)
     DataPtr[I] = 0x55 + I;