diff --git a/clang-tools-extra/clang-tidy/misc/UnconventionalAssignOperatorCheck.cpp b/clang-tools-extra/clang-tidy/misc/UnconventionalAssignOperatorCheck.cpp
index 93ccd5492af764..5fc973223ea3b1 100644
--- a/clang-tools-extra/clang-tidy/misc/UnconventionalAssignOperatorCheck.cpp
+++ b/clang-tools-extra/clang-tidy/misc/UnconventionalAssignOperatorCheck.cpp
@@ -75,7 +75,10 @@ void UnconventionalAssignOperatorCheck::check(
   } else {
     static const char *const Messages[][2] = {
         {"ReturnType", "operator=() should return '%0&'"},
-        {"ArgumentType", "operator=() should take '%0 const&', '%0&&' or '%0'"},
+        {"ArgumentType",
+         getLangOpts().CPlusPlus11
+             ? "operator=() should take '%0 const&', '%0&&' or '%0'"
+             : "operator=() should take '%0 const&' or '%0'"},
         {"cv", "operator=() should not be marked '%1'"}};
 
     const auto *Method = Result.Nodes.getNodeAs<CXXMethodDecl>("method");
diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc-unconventional-assign-operator-precxx11.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc-unconventional-assign-operator-precxx11.cpp
new file mode 100644
index 00000000000000..7dc939955f37a4
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/misc-unconventional-assign-operator-precxx11.cpp
@@ -0,0 +1,6 @@
+// RUN: %check_clang_tidy -std=c++98,c++03 %s misc-unconventional-assign-operator %t
+
+struct BadArgument {
+  BadArgument &operator=(BadArgument &);
+  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: operator=() should take 'BadArgument const&' or 'BadArgument'
+};