diff --git a/lib/symboldatabase.cpp b/lib/symboldatabase.cpp
index 8bb492fa3..501044f1b 100644
--- a/lib/symboldatabase.cpp
+++ b/lib/symboldatabase.cpp
@@ -1008,6 +1008,10 @@ void SymbolDatabase::addFunction(Scope **scope, const Token **tok, const Token *
     else
         tok1 = (*tok)->tokAt(-2);
 
+    // syntax error?
+    if (!tok1)
+        return;
+
     // back up to head of path
     while (tok1 && tok1->previous() && tok1->previous()->str() == "::")
     {
diff --git a/test/testsymboldatabase.cpp b/test/testsymboldatabase.cpp
index 0c81cc14f..69d970c88 100644
--- a/test/testsymboldatabase.cpp
+++ b/test/testsymboldatabase.cpp
@@ -121,6 +121,7 @@ private:
         TEST_CASE(symboldatabase16); // ticket #2637
         TEST_CASE(symboldatabase17); // ticket #2657
         TEST_CASE(symboldatabase18); // ticket #2865
+        TEST_CASE(symboldatabase19); // ticket #2991 (segmentation fault)
     }
 
     void test_isVariableDeclarationCanHandleNull()
@@ -878,6 +879,14 @@ private:
         ASSERT_EQUALS("", errout.str());
     }
 
+    void symboldatabase19()
+    {
+        // ticket #2991 - segmentation fault
+        check("::y(){x}\n");
+
+        ASSERT_EQUALS("", errout.str());
+    }
+
 };
 
 REGISTER_TEST(TestSymbolDatabase)