diff --git a/lib/curl_sasl.h b/lib/curl_sasl.h
index 25ebfe8f21b010063310c09228b226e2cff64919..d2967b0f3e4fc2fd3f5920f9090547cc77379a87 100644
--- a/lib/curl_sasl.h
+++ b/lib/curl_sasl.h
@@ -22,7 +22,11 @@
  *
  ***************************************************************************/
 
-#include "pingpong.h"
+#include <curl/curl.h>
+
+struct SessionHandle;
+struct connectdata;
+struct ntlmdata;
 
 /* Authentication mechanism values */
 #define SASL_AUTH_NONE          0