diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -4790,6 +4790,7 @@
 def err_template_variable_noparams : Error<
   "extraneous 'template<>' in declaration of variable %0">;
 def err_template_member : Error<"member %0 declared as a template">;
+def err_member_with_template_arguments : Error<"member %0 cannot have template arguments">;
 def err_template_member_noparams : Error<
   "extraneous 'template<>' in declaration of member %0">;
 def err_template_tag_noparams : Error<
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -3395,6 +3395,15 @@
       return nullptr;
     }
 
+    if (isInstField &&
+        D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId) {
+      Diag(D.getIdentifierLoc(), diag::err_member_with_template_arguments)
+          << II
+          << SourceRange(D.getName().TemplateId->LAngleLoc,
+                         D.getName().TemplateId->RAngleLoc)
+          << D.getName().TemplateId->LAngleLoc;
+    }
+
     if (SS.isSet() && !SS.isInvalid()) {
       // The user provided a superfluous scope specifier inside a class
       // definition:
diff --git a/clang/test/SemaCXX/class.cpp b/clang/test/SemaCXX/class.cpp
--- a/clang/test/SemaCXX/class.cpp
+++ b/clang/test/SemaCXX/class.cpp
@@ -208,6 +208,22 @@
 }
 }
 
-struct PR9989 { 
-  static int const PR9989_Member = sizeof PR9989_Member; 
+struct PR9989 {
+  static int const PR9989_Member = sizeof PR9989_Member;
 };
+
+
+namespace GH54151 {
+
+struct S {
+  int i<0>;   // expected-error  {{member 'i' cannot have template arguments}}
+  int j<int>; // expected-error  {{member 'j' cannot have template arguments}}
+};
+
+template <typename T, int N>
+struct U {
+  int i<N>; // expected-error {{member 'i' cannot have template arguments}}
+  int j<T>; // expected-error {{member 'j' cannot have template arguments}}
+};
+
+} // namespace GH54151