diff --git a/library/ecp_curves.c b/library/ecp_curves.c
index ff26a18..a0d5fdc 100644
--- a/library/ecp_curves.c
+++ b/library/ecp_curves.c
@@ -754,6 +754,8 @@
 {
     ECP_VALIDATE_RET( grp != NULL );
     mbedtls_ecp_group_free( grp );
+    
+    mbedtls_ecp_group_init( grp );
 
     grp->id = id;