diff --git a/connectivity/mbedtls/source/ecp_curves.c b/connectivity/mbedtls/source/ecp_curves.c
index 839fb5e36e9..72dfacd9af7 100644
--- a/connectivity/mbedtls/source/ecp_curves.c
+++ b/connectivity/mbedtls/source/ecp_curves.c
@@ -770,6 +770,8 @@ int mbedtls_ecp_group_load( mbedtls_ecp_group *grp, mbedtls_ecp_group_id id )
     ECP_VALIDATE_RET( grp != NULL );
     mbedtls_ecp_group_free( grp );
 
+    mbedtls_ecp_group_init( grp );
+
     grp->id = id;
 
     switch( id )