diff --git a/library/des.c b/library/des.c
index 8a33d82..fca2ece 100644
--- a/library/des.c
+++ b/library/des.c
@@ -311,7 +311,7 @@
 
 void mbedtls_des_init( mbedtls_des_context *ctx )
 {
-    memset( ctx, 0, sizeof( mbedtls_des_context ) );
+    mbedtls_platform_memset( ctx, 0, sizeof( mbedtls_des_context ) );
 }
 
 void mbedtls_des_free( mbedtls_des_context *ctx )
@@ -324,7 +324,7 @@
 
 void mbedtls_des3_init( mbedtls_des3_context *ctx )
 {
-    memset( ctx, 0, sizeof( mbedtls_des3_context ) );
+    mbedtls_platform_memset( ctx, 0, sizeof( mbedtls_des3_context ) );
 }
 
 void mbedtls_des3_free( mbedtls_des3_context *ctx )