diff --git a/lib/symboldatabase.cpp b/lib/symboldatabase.cpp
index 91e1e4215..6da6641d5 100644
--- a/lib/symboldatabase.cpp
+++ b/lib/symboldatabase.cpp
@@ -1358,6 +1358,9 @@ bool SymbolDatabase::isFunction(const Token *tok, const Scope* outerScope, const
         const Token* tok1 = tok->previous();
         const Token* tok2 = tok->next()->link()->next();
 
+        if (!_tokenizer->isFunctionHead(tok->next(), ";:{"))
+            return false;
+
         // skip over destructor "~"
         if (tok1->str() == "~")
             tok1 = tok1->previous();
diff --git a/lib/symboldatabase.h b/lib/symboldatabase.h
index d924055ae..2dfe98a00 100644
--- a/lib/symboldatabase.h
+++ b/lib/symboldatabase.h
@@ -1109,6 +1109,7 @@ public:
 
 
 class CPPCHECKLIB SymbolDatabase {
+    friend class TestSymbolDatabase;
 public:
     SymbolDatabase(const Tokenizer *tokenizer, const Settings *settings, ErrorLogger *errorLogger);
     ~SymbolDatabase();
diff --git a/test/testsymboldatabase.cpp b/test/testsymboldatabase.cpp
index 8b9b8ae43..4e4402036 100644
--- a/test/testsymboldatabase.cpp
+++ b/test/testsymboldatabase.cpp
@@ -296,7 +296,8 @@ private:
         TEST_CASE(isImplicitlyVirtual);
         TEST_CASE(isPure);
 
-        TEST_CASE(isFunction); // UNKNOWN_MACRO(a,b) { .. }
+        TEST_CASE(isFunction1); // UNKNOWN_MACRO(a,b) { .. }
+        TEST_CASE(isFunction2);
 
         TEST_CASE(findFunction1);
         TEST_CASE(findFunction2); // mismatch: parameter passed by address => reference argument
@@ -3745,7 +3746,8 @@ private:
             ASSERT(!(it++)->isPure());
         }
     }
-    void isFunction() { // #5602 - UNKNOWN_MACRO(a,b) { .. }
+
+    void isFunction1() { // #5602 - UNKNOWN_MACRO(a,b) { .. }
         GET_SYMBOL_DB("TEST(a,b) {\n"
                       "  std::vector<int> messages;\n"
                       "  foo(messages[2].size());\n"
@@ -3758,6 +3760,25 @@ private:
                var->typeStartToken()->str() == "std");
     }
 
+    void isFunction2() {
+        GET_SYMBOL_DB("void set_cur_cpu_spec()\n"
+                      "{\n"
+                      "    t = PTRRELOC(t);\n"
+                      "}\n"
+                      "\n"
+                      "cpu_spec * __init setup_cpu_spec()\n"
+                      "{\n"
+                      "    t = PTRRELOC(t);\n"
+                      "    *PTRRELOC(&x) = &y;\n"
+                      "}");
+        ASSERT(db != nullptr);
+        ASSERT(db && !db->isFunction(Token::findsimplematch(tokenizer.tokens(), "PTRRELOC ( &"), &db->scopeList.back(), nullptr, nullptr, nullptr));
+        ASSERT(db->findScopeByName("set_cur_cpu_spec") != nullptr);
+        // TODO: ASSERT(db->findScopeByName("setup_cpu_spec") != nullptr);
+        ASSERT(db->findScopeByName("PTRRELOC") == nullptr);
+    }
+
+
     void findFunction1() {
         GET_SYMBOL_DB("int foo(int x);\n" /* 1 */
                       "void foo();\n"     /* 2 */