diff --git a/src/testlib/qtestcase.cpp b/src/testlib/qtestcase.cpp
index 1f694290534..05a3dbbbcb1 100644
--- a/src/testlib/qtestcase.cpp
+++ b/src/testlib/qtestcase.cpp
@@ -2709,8 +2709,11 @@ template <> Q_TESTLIB_EXPORT char *QTest::toString<char>(const char &t)
  */
 char *QTest::toString(const char *str)
 {
-    if (!str)
-        return 0;
+    if (!str) {
+        char *msg = new char[1];
+        *msg = '\0';
+        return msg;
+    }
     char *msg = new char[strlen(str) + 1];
     return qstrcpy(msg, str);
 }