diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc
index 9d0914435fb119a5a38df7ce9c70eefde749c1e1..b2ed2baa3a5701598f1c3cdb315591982751da2d 100644
--- a/gcc/cp/parser.cc
+++ b/gcc/cp/parser.cc
@@ -25724,8 +25724,15 @@ cp_parser_parameter_declaration (cp_parser *parser,
      for a C-style variadic function. */
   token = cp_lexer_peek_token (parser->lexer);
 
-  bool const xobj_param_p
+  bool xobj_param_p
     = decl_spec_seq_has_spec_p (&decl_specifiers, ds_this);
+  if (xobj_param_p && template_parm_p)
+    {
+      error_at (decl_specifiers.locations[ds_this],
+		"%<this%> specifier in template parameter declaration");
+      xobj_param_p = false;
+      decl_specifiers.locations[ds_this] = 0;
+    }
 
   if (xobj_param_p
       && ((declarator && declarator->parameter_pack_p)
diff --git a/gcc/testsuite/g++.dg/parse/pr113929.C b/gcc/testsuite/g++.dg/parse/pr113929.C
new file mode 100644
index 0000000000000000000000000000000000000000..4410f7bf85a79d7f86130e37cdbf7cb2ba8ca786
--- /dev/null
+++ b/gcc/testsuite/g++.dg/parse/pr113929.C
@@ -0,0 +1,7 @@
+// PR c++/113929
+// { dg-do compile }
+
+template <this int C>		// { dg-error "'this' specifier in template parameter declaration" }
+struct S {};
+template <int N, this int C>	// { dg-error "'this' specifier in template parameter declaration" }
+struct T {};