diff --git a/lib/curl_setup.h b/lib/curl_setup.h
index 09c01be482..bd30ba9cbc 100644
--- a/lib/curl_setup.h
+++ b/lib/curl_setup.h
@@ -1105,7 +1105,9 @@ typedef unsigned int curl_bit;
 #define SOCKEINVAL        WSAEINVAL
 #define SOCKEISCONN       WSAEISCONN
 #define SOCKEMSGSIZE      WSAEMSGSIZE
-#define SOCKENOMEM        WSA_NOT_ENOUGH_MEMORY
+/* Use literal value to work around clang-tidy <=20 misreporting
+  'readability-uppercase-literal-suffix' with mingw-w64 headers */
+#define SOCKENOMEM        8L  /* WSA_NOT_ENOUGH_MEMORY */
 #define SOCKETIMEDOUT     WSAETIMEDOUT
 #define SOCKEWOULDBLOCK   WSAEWOULDBLOCK
 #else