diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index 4cc28c3..be4d011 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -233,7 +233,7 @@
     unsigned char *p = buf;
     unsigned char elliptic_curve_list[20];
     size_t elliptic_curve_len = 0;
-    ecp_curve_info *curve;
+    const ecp_curve_info *curve;
     ((void) ssl);
 
     *olen = 0;