diff --git a/lib/token.cpp b/lib/token.cpp
index 9cbc51f4e..df8bcca0f 100644
--- a/lib/token.cpp
+++ b/lib/token.cpp
@@ -1103,8 +1103,11 @@ void Token::astOperand1(Token *tok)
         _astOperand1->_astParent = nullptr;
     // goto parent operator
     if (tok) {
-        while (tok->_astParent)
+        while (tok->_astParent) {
+            if (tok->_astParent == this) // #6838 avoid hang on garbage code
+                throw InternalError(this, "Internal error. oken::astOperand1() recursive dependency.");
             tok = tok->_astParent;
+        }
         tok->_astParent = this;
     }
     _astOperand1 = tok;
@@ -1116,8 +1119,11 @@ void Token::astOperand2(Token *tok)
         _astOperand2->_astParent = nullptr;
     // goto parent operator
     if (tok) {
-        while (tok->_astParent)
+        while (tok->_astParent) {
+            if (tok->_astParent == this) // #6838 avoid hang on garbage code
+                throw InternalError(this, "Internal error. oken::astOperand1() recursive dependency.");
             tok = tok->_astParent;
+        }
         tok->_astParent = this;
     }
     _astOperand2 = tok;
diff --git a/test/testgarbage.cpp b/test/testgarbage.cpp
index 2870cba02..080b03b02 100644
--- a/test/testgarbage.cpp
+++ b/test/testgarbage.cpp
@@ -137,6 +137,7 @@ private:
         TEST_CASE(garbageCode95);
         TEST_CASE(garbageCode96);
         TEST_CASE(garbageCode97);
+        TEST_CASE(garbageCode98);
 
         TEST_CASE(garbageValueFlow);
         TEST_CASE(garbageSymbolDatabase);
@@ -761,6 +762,12 @@ private:
         ASSERT_THROW(checkCode("namespace A {> } class A{ { }} class A : T< ;"), InternalError);
     }
 
+    void garbageCode98() { // #6838
+        ASSERT_THROW(checkCode("for (cocon To::ta@Taaaaaforconst oken aaaaaaaaaaaa5Dl()\n"
+                               "const unsiged in;\n"
+                               "fon *tok = f);.s(Token i = d-)L;"), InternalError);
+    }
+
     void garbageValueFlow() {
         // #6089
         const char* code = "{} int foo(struct, x1, struct x2, x3, int, x5, x6, x7)\n"