diff --git a/lib/http_ntlm.c b/lib/http_ntlm.c
index fd9f7009c83c68b7652b099cd4c340ef68ea0377..ca81a947d76ab1ae7886983d4602304de71dcf98 100644
--- a/lib/http_ntlm.c
+++ b/lib/http_ntlm.c
@@ -62,6 +62,12 @@
 #define _MPRINTF_REPLACE /* use our functions only */
 #include <curl/mprintf.h>
 
+#if defined(USE_NSS)
+#include "nssg.h"
+#elif defined(USE_WINDOWS_SSPI)
+#include "curl_sspi.h"
+#endif
+
 /* The last #include file should be: */
 #include "memdebug.h"