diff --git a/include/iscsi-private.h b/include/iscsi-private.h
index a905056..9eca824 100644
--- a/include/iscsi-private.h
+++ b/include/iscsi-private.h
@@ -299,8 +299,13 @@ int iscsi_process_reject(struct iscsi_context *iscsi,
 				struct iscsi_in_pdu *in);
 int iscsi_send_target_nop_out(struct iscsi_context *iscsi, uint32_t ttt);
 
+#if defined(WIN32)
+void iscsi_set_error(struct iscsi_context *iscsi, const char *error_string,
+		     ...);
+#else
 void iscsi_set_error(struct iscsi_context *iscsi, const char *error_string,
 		     ...) __attribute__((format(printf, 2, 3)));
+#endif
 
 struct scsi_iovector *iscsi_get_scsi_task_iovector_in(struct iscsi_context *iscsi, struct iscsi_in_pdu *in);
 struct scsi_iovector *iscsi_get_scsi_task_iovector_out(struct iscsi_context *iscsi, struct iscsi_pdu *pdu);