diff --git a/programs/x509/cert_write.c b/programs/x509/cert_write.c
index bccc3b7..f0f044d 100644
--- a/programs/x509/cert_write.c
+++ b/programs/x509/cert_write.c
@@ -145,8 +145,9 @@
     "    is_ca=%%d                default: 0 (disabled)\n"  \
     "    max_pathlen=%%d          default: -1 (none)\n"     \
     "    md=%%s                   default: SHA256\n"        \
-    "                            Supported values:\n"       \
-    "                            MD2, MD4, MD5, SHA1, SHA256, SHA512\n"\
+    "                            Supported values (if enabled):\n"      \
+    "                            MD2, MD4, MD5, RIPEMD160, SHA1,\n" \
+    "                            SHA224, SHA256, SHA384, SHA512\n" \
     "    version=%%d              default: 3\n"            \
     "                            Possible values: 1, 2, 3\n"\
     "    subject_identifier=%%s   default: 1\n"             \
@@ -380,23 +381,14 @@
         }
         else if( strcmp( p, "md" ) == 0 )
         {
-            if( strcmp( q, "SHA1" ) == 0 )
-                opt.md = MBEDTLS_MD_SHA1;
-            else if( strcmp( q, "SHA256" ) == 0 )
-                opt.md = MBEDTLS_MD_SHA256;
-            else if( strcmp( q, "SHA512" ) == 0 )
-                opt.md = MBEDTLS_MD_SHA512;
-            else if( strcmp( q, "MD2" ) == 0 )
-                opt.md = MBEDTLS_MD_MD2;
-            else if( strcmp( q, "MD4" ) == 0 )
-                opt.md = MBEDTLS_MD_MD4;
-            else if( strcmp( q, "MD5" ) == 0 )
-                opt.md = MBEDTLS_MD_MD5;
-            else
+            const mbedtls_md_info_t *md_info =
+                mbedtls_md_info_from_string( q );
+            if( md_info == NULL )
             {
                 mbedtls_printf( "Invalid argument for option %s\n", p );
                 goto usage;
             }
+            opt.md = mbedtls_md_get_type( md_info );
         }
         else if( strcmp( p, "version" ) == 0 )
         {