diff --git a/lib/checkclass.cpp b/lib/checkclass.cpp
index 25314d6be4f..66ab3578560 100644
--- a/lib/checkclass.cpp
+++ b/lib/checkclass.cpp
@@ -3311,7 +3311,7 @@ static const Variable* getSingleReturnVar(const Scope* scope) {
     const Token* const end = Token::findsimplematch(start, ";", 1, scope->bodyEnd);
     if (!end || end->next() != scope->bodyEnd)
         return nullptr;
-    if (start->str() != "return")
+    if (!start->astOperand1() || start->str() != "return")
         return nullptr;
     return start->astOperand1()->variable();
 }
diff --git a/test/testclass.cpp b/test/testclass.cpp
index e6fb80f002e..dc39d59b76f 100644
--- a/test/testclass.cpp
+++ b/test/testclass.cpp
@@ -8985,6 +8985,7 @@ class TestClass : public TestFixture {
                                "    T getT() const { return t; }"
                                "    int getI() const { return i; }"
                                "    std::string getS() const { return s; }"
+                               "    unknown_t f() { return; }"
                                "};");
         ASSERT_EQUALS("[test.cpp:1]: (performance) Function 'getT()' should return member 't' by const reference.\n"
                       "[test.cpp:1]: (performance) Function 'getS()' should return member 's' by const reference.\n",