diff --git a/lib/templatesimplifier.cpp b/lib/templatesimplifier.cpp
index 0f1e8c809..14fe48163 100644
--- a/lib/templatesimplifier.cpp
+++ b/lib/templatesimplifier.cpp
@@ -850,7 +850,13 @@ void TemplateSimplifier::getTemplateInstantiations()
             // look for function instantiation with type deduction
             // fixme: only single argument functions supported
             if (tok->strAt(1) == "(") {
-                std::string fullName = qualification + (qualification.empty() ? "" : " :: ") + tok->str();
+                std::string fullName;
+                if (!qualification.empty())
+                    fullName = qualification + " :: " + tok->str();
+                else if (!scopeName.empty())
+                    fullName = scopeName + " :: " + tok->str();
+                else
+                    fullName = tok->str();
                 // get all declarations with this name
                 for (auto pos = functionNameMap.lower_bound(tok->str());
                      pos != functionNameMap.upper_bound(tok->str()); ++pos) {
diff --git a/test/testsimplifytemplate.cpp b/test/testsimplifytemplate.cpp
index d84211abc..17b8caa94 100644
--- a/test/testsimplifytemplate.cpp
+++ b/test/testsimplifytemplate.cpp
@@ -247,6 +247,7 @@ private:
 
         TEST_CASE(templateTypeDeduction1); // #8962
         TEST_CASE(templateTypeDeduction2);
+        TEST_CASE(templateTypeDeduction3);
 
         TEST_CASE(simplifyTemplateArgs1);
         TEST_CASE(simplifyTemplateArgs2);
@@ -5258,6 +5259,28 @@ private:
         TODO_ASSERT_EQUALS(expected, actual, tok(code));
     }
 
+    void templateTypeDeduction3() {  // #9975
+        const char code[] = "struct A {\n"
+                            "    int a = 1;\n"
+                            "    void f() { g(1); }\n"
+                            "    template <typename T> void g(T x) { a = 2; }\n"
+                            "};\n"
+                            "int main() {\n"
+                            "    A a;\n"
+                            "    a.f();\n"
+                            "}";
+        const char exp[]  = "struct A { "
+                            "int a ; a = 1 ; "
+                            "void f ( ) { g<int> ( 1 ) ; } "
+                            "void g<int> ( int x ) ; "
+                            "} ; "
+                            "int main ( ) { "
+                            "A a ; "
+                            "a . f ( ) ; "
+                            "} void A :: g<int> ( int x ) { a = 2 ; }";
+        ASSERT_EQUALS(exp, tok(code));
+    }
+
     void simplifyTemplateArgs1() {
         ASSERT_EQUALS("foo<2> = 2 ; foo<2> ;", tok("template<int N> foo = N; foo < ( 2 ) >;"));
         ASSERT_EQUALS("foo<2> = 2 ; foo<2> ;", tok("template<int N> foo = N; foo < 1 + 1 >;"));