diff --git a/lib/mprintf.c b/lib/mprintf.c
index 6a41d36f62..11551a5d7a 100644
--- a/lib/mprintf.c
+++ b/lib/mprintf.c
@@ -455,15 +455,30 @@ static int parsefmt(const char *format,
         flags |= FLAGS_UNSIGNED;
         break;
       case 'o':
-        type = FORMAT_INT;
+        if(flags & FLAGS_LONGLONG)
+          type = FORMAT_LONGLONG;
+        else if(flags & FLAGS_LONG)
+          type = FORMAT_LONG;
+        else
+          type = FORMAT_INT;
         flags |= FLAGS_OCTAL;
         break;
       case 'x':
-        type = FORMAT_INTU;
+        if(flags & FLAGS_LONGLONG)
+          type = FORMAT_LONGLONGU;
+        else if(flags & FLAGS_LONG)
+          type = FORMAT_LONGU;
+        else
+          type = FORMAT_INTU;
         flags |= FLAGS_HEX|FLAGS_UNSIGNED;
         break;
       case 'X':
-        type = FORMAT_INTU;
+        if(flags & FLAGS_LONGLONG)
+          type = FORMAT_LONGLONGU;
+        else if(flags & FLAGS_LONG)
+          type = FORMAT_LONGU;
+        else
+          type = FORMAT_INTU;
         flags |= FLAGS_HEX|FLAGS_UPPER|FLAGS_UNSIGNED;
         break;
       case 'c':