diff --git a/src/corelib/text/qlocale_tools.cpp b/src/corelib/text/qlocale_tools.cpp
index a8f63a5998..24a6bcfd09 100644
--- a/src/corelib/text/qlocale_tools.cpp
+++ b/src/corelib/text/qlocale_tools.cpp
@@ -362,6 +362,7 @@ double qt_asciiToDouble(const char *num, qsizetype numLen, bool &ok, int &proces
         buffer = reasonableBuffer;
     else
         buffer = static_cast<char *>(malloc(numLen + 1));
+    Q_CHECK_PTR(buffer);
     memcpy(buffer, num, numLen);
     buffer[numLen] = '\0';