diff --git a/library/ecdh.c b/library/ecdh.c
index 4f50e6ef1..9c4ddce9c 100644
--- a/library/ecdh.c
+++ b/library/ecdh.c
@@ -186,7 +186,6 @@ static void ecdh_init_internal( mbedtls_ecdh_context_mbed *ctx )
 void mbedtls_ecdh_init( mbedtls_ecdh_context *ctx )
 {
     ECDH_VALIDATE( ctx != NULL );
-    memset( ctx, 0, sizeof( mbedtls_ecdh_context ) );
 
 #if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
     ecdh_init_internal( ctx );
@@ -194,6 +193,8 @@ void mbedtls_ecdh_init( mbedtls_ecdh_context *ctx )
     mbedtls_ecp_point_init( &ctx->Vf  );
     mbedtls_mpi_init( &ctx->_d );
 #else
+    memset( ctx, 0, sizeof( mbedtls_ecdh_context ) );
+
     ctx->var = MBEDTLS_ECDH_VARIANT_NONE;
 #endif
     ctx->point_format = MBEDTLS_ECP_PF_UNCOMPRESSED;