diff --git a/src/tools/atoi36.c b/src/tools/atoi36.c
index 0586d2788..a935e7650 100644
--- a/src/tools/atoi36.c
+++ b/src/tools/atoi36.c
@@ -12,12 +12,24 @@
 
 #include <base36.h>
 #include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
 
 int main(int argc, char**argv)
 {
-  int i;
-  for (i=1;i!=argc;++i) {
-    printf("%s -> %d\n", argv[i], atoi36(argv[i]));
+  int i=1, reverse = 0;
+  if (strstr(argv[0], "itoa36")) reverse=1;
+  if (argc>1) {
+    if (strcmp(argv[1], "-r")==0) {
+      i=2;
+      reverse=1;
+    }
+  }
+  for (;i!=argc;++i) {
+    if (reverse) {
+      printf("%s -> %s\n", argv[i], itoa36(atoi(argv[i])));
+    }
+    else printf("%s -> %d\n", argv[i], atoi36(argv[i]));
   }
   return 0;
 }