diff --git a/ChangeLog b/ChangeLog
index e9b67908f..11cc52294 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -11,6 +11,8 @@ Bugfix
    * Fix issue in Makefile that prevented building using armar. #386
    * Fix memory leak that occured only when ECJPAKE was enabled and ECDHE and
      ECDSA was disabled in config.h . The leak didn't occur by default.
+   * Fix issue that caused a crash if invalid curves were passed to
+     mbedtls_ssl_conf_curves. #373
 
 Changes
    * On ARM platforms, when compiling with -O0 with GCC, Clang or armcc5,
diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index 4452169d9..785c01fbe 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -270,6 +270,12 @@ static void ssl_write_supported_elliptic_curves_ext( mbedtls_ssl_context *ssl,
     for( info = mbedtls_ecp_curve_list(); info->grp_id != MBEDTLS_ECP_DP_NONE; info++ )
     {
 #endif
+        if( info == NULL )
+        {
+            MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid curve in ssl configuration" ) );
+            return;
+        }
+
         elliptic_curve_len += 2;
     }
 
@@ -289,7 +295,6 @@ static void ssl_write_supported_elliptic_curves_ext( mbedtls_ssl_context *ssl,
     for( info = mbedtls_ecp_curve_list(); info->grp_id != MBEDTLS_ECP_DP_NONE; info++ )
     {
 #endif
-
         elliptic_curve_list[elliptic_curve_len++] = info->tls_id >> 8;
         elliptic_curve_list[elliptic_curve_len++] = info->tls_id & 0xFF;
     }