diff --git a/library/des.c b/library/des.c
index 79c81bc2f..2f06af3d2 100644
--- a/library/des.c
+++ b/library/des.c
@@ -837,15 +837,12 @@ int des_self_test( int verbose )
     int i, j, u, v;
     des_context ctx;
     des3_context ctx3;
-    unsigned char key[24];
     unsigned char buf[8];
 #if defined(POLARSSL_CIPHER_MODE_CBC)
     unsigned char prv[8];
     unsigned char iv[8];
 #endif
 
-    memset( key, 0, 24 );
-
     /*
      * ECB mode
      */
diff --git a/library/gcm.c b/library/gcm.c
index a89207615..62fe1852b 100644
--- a/library/gcm.c
+++ b/library/gcm.c
@@ -195,7 +195,6 @@ static void gcm_mult( gcm_context *ctx, const unsigned char x[16],
                       unsigned char output[16] )
 {
     int i = 0;
-    unsigned char z[16];
     unsigned char lo, hi, rem;
     uint64_t zh, zl;
 
@@ -213,8 +212,6 @@ static void gcm_mult( gcm_context *ctx, const unsigned char x[16],
     }
 #endif /* POLARSSL_AESNI_C && POLARSSL_HAVE_X86_64 */
 
-    memset( z, 0x00, 16 );
-
     lo = x[15] & 0xf;
     hi = x[15] >> 4;