diff --git a/programs/aes/aescrypt2.c b/programs/aes/aescrypt2.c
index 048028d..8edf85f 100644
--- a/programs/aes/aescrypt2.c
+++ b/programs/aes/aescrypt2.c
@@ -118,7 +118,7 @@
     ret = mbedtls_md_setup( &sha_ctx, mbedtls_md_info_from_type( MBEDTLS_MD_SHA256 ), 1 );
     if( ret != 0 )
     {
-        mbedtls_printf( "  ! mbedtls_md_setup() returned -0x%04x\n", -ret );
+        mbedtls_printf( "  ! mbedtls_md_setup() returned -0x%04x\n", (unsigned int) -ret );
         goto exit;
     }
 
@@ -298,7 +298,7 @@
 
             if( fread( buffer, 1, n, fin ) != (size_t) n )
             {
-                mbedtls_fprintf( stderr, "fread(%d bytes) failed\n", n );
+                mbedtls_fprintf( stderr, "fread(%u bytes) failed\n", n );
                 goto exit;
             }
 
@@ -413,7 +413,7 @@
 
             if( fwrite( buffer, 1, n, fout ) != (size_t) n )
             {
-                mbedtls_fprintf( stderr, "fwrite(%d bytes) failed\n", n );
+                mbedtls_fprintf( stderr, "fwrite(%u bytes) failed\n", n );
                 goto exit;
             }
         }
diff --git a/programs/aes/crypt_and_hash.c b/programs/aes/crypt_and_hash.c
index a5acf5b..e2949f2 100644
--- a/programs/aes/crypt_and_hash.c
+++ b/programs/aes/crypt_and_hash.c
@@ -219,7 +219,7 @@
             p = &argv[6][4];
             keylen = 0;
 
-            while( sscanf( p, "%02X", &n ) > 0 &&
+            while( sscanf( p, "%02X", (unsigned int*) &n ) > 0 &&
                    keylen < (int) sizeof( key ) )
             {
                 key[keylen++] = (unsigned char) n;
@@ -417,7 +417,7 @@
             ( ( filesize - mbedtls_md_get_size( md_info ) ) %
                 mbedtls_cipher_get_block_size( &cipher_ctx ) ) != 0 )
         {
-            mbedtls_fprintf( stderr, "File content not a multiple of the block size (%d).\n",
+            mbedtls_fprintf( stderr, "File content not a multiple of the block size (%u).\n",
                      mbedtls_cipher_get_block_size( &cipher_ctx ));
             goto exit;
         }
@@ -484,7 +484,7 @@
 
             if( fread( buffer, 1, ilen, fin ) != ilen )
             {
-                mbedtls_fprintf( stderr, "fread(%d bytes) failed\n",
+                mbedtls_fprintf( stderr, "fread(%u bytes) failed\n",
                     mbedtls_cipher_get_block_size( &cipher_ctx ) );
                 goto exit;
             }