diff --git a/llvm/lib/Target/AArch64/AArch64RegisterInfo.cpp b/llvm/lib/Target/AArch64/AArch64RegisterInfo.cpp
index 3e9c8c7b6df2..f719cc6e5e4e 100644
--- a/llvm/lib/Target/AArch64/AArch64RegisterInfo.cpp
+++ b/llvm/lib/Target/AArch64/AArch64RegisterInfo.cpp
@@ -334,8 +334,8 @@ bool AArch64RegisterInfo::isAnyArgRegReserved(const MachineFunction &MF) const {
 void AArch64RegisterInfo::emitReservedArgRegCallError(
     const MachineFunction &MF) const {
   const Function &F = MF.getFunction();
-  F.getContext().diagnose(DiagnosticInfoUnsupported{F, "AArch64 doesn't support"
-    " function calls if any of the argument registers is reserved."});
+  F.getContext().diagnose(DiagnosticInfoUnsupported{F, ("AArch64 doesn't support"
+    " function calls if any of the argument registers is reserved.")});
 }
 
 bool AArch64RegisterInfo::isAsmClobberable(const MachineFunction &MF,