diff --git a/include/curl/curl.h b/include/curl/curl.h
index 36038494b3..a34598d352 100644
--- a/include/curl/curl.h
+++ b/include/curl/curl.h
@@ -2363,18 +2363,18 @@ enum CURL_NETRC_OPTION {
   CURL_NETRC_LAST = 3
 };
 
-#define CURL_SSLVERSION_DEFAULT 0
-#define CURL_SSLVERSION_TLSv1   1 /* TLS 1.x */
-#define CURL_SSLVERSION_SSLv2   2
-#define CURL_SSLVERSION_SSLv3   3
-#define CURL_SSLVERSION_TLSv1_0 4
-#define CURL_SSLVERSION_TLSv1_1 5
-#define CURL_SSLVERSION_TLSv1_2 6
-#define CURL_SSLVERSION_TLSv1_3 7
+#define CURL_SSLVERSION_DEFAULT 0L
+#define CURL_SSLVERSION_TLSv1   1L /* TLS 1.x */
+#define CURL_SSLVERSION_SSLv2   2L
+#define CURL_SSLVERSION_SSLv3   3L
+#define CURL_SSLVERSION_TLSv1_0 4L
+#define CURL_SSLVERSION_TLSv1_1 5L
+#define CURL_SSLVERSION_TLSv1_2 6L
+#define CURL_SSLVERSION_TLSv1_3 7L
 
-#define CURL_SSLVERSION_LAST 8 /* never use, keep last */
+#define CURL_SSLVERSION_LAST    8L /* never use, keep last */
 
-#define CURL_SSLVERSION_MAX_NONE 0
+#define CURL_SSLVERSION_MAX_NONE 0L
 #define CURL_SSLVERSION_MAX_DEFAULT (CURL_SSLVERSION_TLSv1   << 16)
 #define CURL_SSLVERSION_MAX_TLSv1_0 (CURL_SSLVERSION_TLSv1_0 << 16)
 #define CURL_SSLVERSION_MAX_TLSv1_1 (CURL_SSLVERSION_TLSv1_1 << 16)