diff --git a/clang/include/clang/Basic/Builtins.def b/clang/include/clang/Basic/Builtins.def
index 984e607..08c999a 100644
--- a/clang/include/clang/Basic/Builtins.def
+++ b/clang/include/clang/Basic/Builtins.def
@@ -440,7 +440,7 @@
 BUILTIN(__builtin_rotateright8, "UcUcUc", "nc")
 BUILTIN(__builtin_rotateright16, "UsUsUs", "nc")
 BUILTIN(__builtin_rotateright32, "UZiUZiUZi", "nc")
-BUILTIN(__builtin_rotateright64, "UWiUWiWi", "nc")
+BUILTIN(__builtin_rotateright64, "UWiUWiUWi", "nc")
 
 // Random GCC builtins
 BUILTIN(__builtin_constant_p, "i.", "nctu")
diff --git a/clang/test/CodeGen/avr-builtins.c b/clang/test/CodeGen/avr-builtins.c
index cbba6b2..8fa983a 100644
--- a/clang/test/CodeGen/avr-builtins.c
+++ b/clang/test/CodeGen/avr-builtins.c
@@ -1,5 +1,9 @@
 // RUN: %clang_cc1 -triple avr-unknown-unknown -emit-llvm -o - %s | FileCheck %s
 
+// Check that the parameter types match. This verifies pr43309.
+// RUN: %clang_cc1 -triple avr-unknown-unknown -Wconversion -verify %s
+// expected-no-diagnostics
+
 unsigned char bitrev8(unsigned char data) {
     return __builtin_bitreverse8(data);
 }