diff --git a/lib/templatesimplifier.cpp b/lib/templatesimplifier.cpp
index f4b7706d6..1fa2dacd2 100644
--- a/lib/templatesimplifier.cpp
+++ b/lib/templatesimplifier.cpp
@@ -1080,8 +1080,34 @@ void TemplateSimplifier::expandTemplate(
                         dst->insertToken(newName, "", true);
                         if (start->strAt(1) == "<")
                             start = start->next()->findClosingBracket();
-                    } else
-                        dst->insertToken(start->str(), "", true);
+                    } else {
+                        // check if type is a template
+                        if (start->strAt(1) == "<") {
+                            // get the instantiated name
+                            Token * closing = start->next()->findClosingBracket();
+                            std::string name;
+                            const Token * type = start;
+                            while (type && type != closing->next()) {
+                                if (!name.empty())
+                                    name += " ";
+                                name += type->str();
+                                type = type->next();
+                            }
+                            // check if type is instantiated
+                            for (const auto & inst : mTemplateInstantiations) {
+                                if (Token::simpleMatch(inst.nameToken, name.c_str())) {
+                                    // use the instantiated name
+                                    dst->insertToken(name, "", true);
+                                    start = closing;
+                                    break;
+                                }
+                            }
+                            // just copy the token if it wasn't instantiated
+                            if (start != closing)
+                                dst->insertToken(start->str(), "", true);
+                        } else
+                            dst->insertToken(start->str(), "", true);
+                    }
                     if (start->link()) {
                         if (Token::Match(start, "[|{|(")) {
                             links[start->link()] = dst->previous();
diff --git a/test/testsimplifytemplate.cpp b/test/testsimplifytemplate.cpp
index 786ec42cb..adafba8db 100644
--- a/test/testsimplifytemplate.cpp
+++ b/test/testsimplifytemplate.cpp
@@ -119,6 +119,7 @@ private:
         TEST_CASE(template79); // #5133
         TEST_CASE(template80);
         TEST_CASE(template81);
+        TEST_CASE(template82); // 8603
         TEST_CASE(template_specialization_1);  // #7868 - template specialization template <typename T> struct S<C<T>> {..};
         TEST_CASE(template_specialization_2);  // #7868 - template specialization template <typename T> struct S<C<T>> {..};
         TEST_CASE(template_enum);  // #6299 Syntax error in complex enum declaration (including template)
@@ -1554,6 +1555,44 @@ private:
         ASSERT_EQUALS(exp, tok(code));
     }
 
+    void template82() { // 8603
+        const char code[] = "typedef int comp;\n"
+                            "const int f16=16;\n"
+                            "template<int x>\n"
+                            "class tvec2 {};\n"
+                            "template<int x>\n"
+                            "class tvec3 {};\n"
+                            "namespace swizzle {\n"
+                            "template <comp> void swizzle(tvec2<f16> v) { }\n"
+                            "template <comp x, comp y> void swizzle(tvec3<f16> v) { }\n"
+                            "}\n"
+                            "void foo() {\n"
+                            "  using namespace swizzle;\n"
+                            "  tvec2<f16> tt2;\n"
+                            "  swizzle<1>(tt2);\n"
+                            "  tvec3<f16> tt3;\n"
+                            "  swizzle<2,3>(tt3);\n"
+                            "}";
+        const char exp[] = "class tvec2<f16> ; "
+                           "class tvec3<f16> ; "
+                           "namespace swizzle { "
+                           "void swizzle<1> ( tvec2<f16> v ) ; "
+                           "void swizzle<2,3> ( tvec3<f16> v ) ; "
+                           "} "
+                           "void foo ( ) { "
+                           "using namespace swizzle ; "
+                           "tvec2<f16> tt2 ; "
+                           "swizzle<1> ( tt2 ) ; "
+                           "tvec3<f16> tt3 ; "
+                           "swizzle<2,3> ( tt3 ) ; "
+                           "} "
+                           "void swizzle :: swizzle<2,3> ( tvec3<f16> v ) { } "
+                           "void swizzle :: swizzle<1> ( tvec2<f16> v ) { } "
+                           "class tvec3<f16> { } ; "
+                           "class tvec2<f16> { } ;";
+        ASSERT_EQUALS(exp, tok(code));
+    }
+
     void template_specialization_1() {  // #7868 - template specialization template <typename T> struct S<C<T>> {..};
         const char code[] = "template <typename T> struct C {};\n"
                             "template <typename T> struct S {a};\n"