diff --git a/lib/tokenize.cpp b/lib/tokenize.cpp
index be1756918..cde47a3e5 100644
--- a/lib/tokenize.cpp
+++ b/lib/tokenize.cpp
@@ -1061,7 +1061,9 @@ void Tokenizer::simplifyTypedef()
                 // check for operator typedef
                 /** @todo add support for multi-token operators */
                 else if (tok2->str() == "operator" &&
+                         tok2->next() &&
                          tok2->next()->str() == typeName->str() &&
+                         tok2->linkAt(2) &&
                          tok2->strAt(2) == "(" &&
                          Token::Match(tok2->linkAt(2), ") const| {")) {
                     // check for qualifier
diff --git a/test/testgarbage.cpp b/test/testgarbage.cpp
index eeb0b77c4..e393ae881 100644
--- a/test/testgarbage.cpp
+++ b/test/testgarbage.cpp
@@ -112,6 +112,7 @@ private:
         TEST_CASE(garbageCode71);
         TEST_CASE(garbageCode72);
         TEST_CASE(garbageCode73);
+        TEST_CASE(garbageCode74);
 
         TEST_CASE(garbageValueFlow);
         TEST_CASE(garbageSymbolDatabase);
@@ -625,6 +626,10 @@ private:
         ASSERT_THROW(checkCode("typedef int IRT[2]; IRT&"), InternalError);
     }
 
+    void garbageCode74() { // #6751
+        checkCode("_lenraw(const char* digits) { } typedef decltype(sizeof(0)) { } operator");
+    }
+
     void garbageValueFlow() {
         // #6089
         const char* code = "{} int foo(struct, x1, struct x2, x3, int, x5, x6, x7)\n"