diff --git a/lib/checkstl.cpp b/lib/checkstl.cpp
index 5bbbf70a0c7..123395b31e3 100644
--- a/lib/checkstl.cpp
+++ b/lib/checkstl.cpp
@@ -2036,6 +2036,8 @@ static const Token *singleMemberCallInScope(const Token *start, nonneg int varid
     if (!Token::findmatch(dotTok->tokAt(2), "%varid%", endStatement, varid))
         return nullptr;
     input = Token::Match(start->next(), "%var% . %name% ( %varid% )", varid);
+    if (!dotTok->astOperand1()) // incomplete code
+        return nullptr;
     if (isVariableChanged(dotTok->next(), endStatement, dotTok->astOperand1()->varId(), false, nullptr, true))
         return nullptr;
     return dotTok;
diff --git a/test/teststl.cpp b/test/teststl.cpp
index 99e861144eb..a20691fb549 100644
--- a/test/teststl.cpp
+++ b/test/teststl.cpp
@@ -3241,6 +3241,20 @@ class TestStl : public TestFixture {
               "    void shift() { EffectivityRangeData<int>::iterator it;  } \n"
               "};\n");
         ASSERT_EQUALS("", errout.str());
+
+        // test for crash in z3
+        check("struct explain::imp {\n"
+              "    solver &m_solver;\n"
+              "\n"
+              "    void project(var x, unsigned num, literal const *ls,\n"
+              "                 const scoped_literal_vector &result) {\n"
+              "        DEBUG_CODE(TRACE(\"nlsat\",\n"
+              "                         for (literal l\n"
+              "                              : result) { m_solver.display(tout << \" \", l); });\n"
+              "                        );\n"
+              "    }\n"
+              "};");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void dereferenceInvalidIterator() {