diff --git a/lib/curl_sasl_sspi.c b/lib/curl_sasl_sspi.c
index 70c4c1877..2c14afdd9 100644
--- a/lib/curl_sasl_sspi.c
+++ b/lib/curl_sasl_sspi.c
@@ -29,6 +29,7 @@
 
 #include <curl/curl.h>
 
+#include "curl_sasl.h"
 #include "urldata.h"
 #include "curl_base64.h"
 #include "warnless.h"