diff --git a/library/ccm.c b/library/ccm.c
index 75de8cb5b9..aa2d6754b4 100644
--- a/library/ccm.c
+++ b/library/ccm.c
@@ -81,6 +81,8 @@ int mbedtls_ccm_setkey( mbedtls_ccm_context *ctx,
     if( cipher_info->block_size != 16 )
         return( MBEDTLS_ERR_CCM_BAD_INPUT );
 
+    mbedtls_cipher_free( &ctx->cipher_ctx );
+
     if( ( ret = mbedtls_cipher_setup( &ctx->cipher_ctx, cipher_info ) ) != 0 )
         return( ret );
 
diff --git a/library/gcm.c b/library/gcm.c
index 79d433a175..a347c06779 100644
--- a/library/gcm.c
+++ b/library/gcm.c
@@ -174,6 +174,8 @@ int mbedtls_gcm_setkey( mbedtls_gcm_context *ctx,
     if( cipher_info->block_size != 16 )
         return( MBEDTLS_ERR_GCM_BAD_INPUT );
 
+    mbedtls_cipher_free( &ctx->cipher_ctx );
+
     if( ( ret = mbedtls_cipher_setup( &ctx->cipher_ctx, cipher_info ) ) != 0 )
         return( ret );