diff --git a/lib/AST/ItaniumMangle.cpp b/lib/AST/ItaniumMangle.cpp
index 3d0e725..e94b4cf 100644
--- a/lib/AST/ItaniumMangle.cpp
+++ b/lib/AST/ItaniumMangle.cpp
@@ -2235,9 +2235,6 @@ void CXXNameMangler::mangleAArch64NeonVectorType(const VectorType *T) {
   assert((BitSize == 64 || BitSize == 128) &&
          "Neon vector type not 64 or 128 bits");
 
-  assert(getASTContext().getTypeSize(EltType) != BitSize &&
-         "Vector of 1 element not permitted");
-
   StringRef EltName;
   if (T->getVectorKind() == VectorType::NeonPolyVector) {
     switch (cast<BuiltinType>(EltType)->getKind()) {
@@ -2247,6 +2244,9 @@ void CXXNameMangler::mangleAArch64NeonVectorType(const VectorType *T) {
     case BuiltinType::UShort:
       EltName = "Poly16";
       break;
+    case BuiltinType::ULongLong:
+      EltName = "Poly64";
+      break;
     default:
       llvm_unreachable("unexpected Neon polynomial vector element type");
     }
diff --git a/test/CodeGenCXX/aarch64-neon.cpp b/test/CodeGenCXX/aarch64-neon.cpp
new file mode 100644
index 0000000..5d2a00b
--- /dev/null
+++ b/test/CodeGenCXX/aarch64-neon.cpp
@@ -0,0 +1,13 @@
+// REQUIRES: aarch64-registered-target
+// RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +neon \
+// RUN:   -ffp-contract=fast -S -O3 -o - %s | FileCheck %s
+
+// Test whether arm_neon.h can be used in .cpp file.
+
+#include "arm_neon.h"
+
+poly64x1_t test_vld1_p64(poly64_t const * ptr) {
+  // CHECK: test_vld1_p64
+  return vld1_p64(ptr);
+  // CHECK:  ld1 {{{v[0-9]+}}.1d}, [{{x[0-9]+|sp}}]
+}