diff --git a/CHANGES b/CHANGES
index ee46cf3..a398fa0 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,6 +1,7 @@
 0.23:
   also recognize EPFNOSUPPORT as EAFNOSUPPORT (groan)
   fix a few man pages
+  optimize fmt_base64 (Dan Gundlach)
 
 0.22:
   uh, the scope_id detection #defined the wrong constant.  libowfat
diff --git a/textcode/fmt_base64.c b/textcode/fmt_base64.c
index 1c1d387..4753445 100644
--- a/textcode/fmt_base64.c
+++ b/textcode/fmt_base64.c
@@ -6,18 +6,19 @@ unsigned long fmt_base64(char* dest,const char* src,unsigned long len) {
   register const unsigned char* s=(const unsigned char*) src;
   unsigned short bits=0,temp=0;
   unsigned long written=0,i;
+  if (!dest) return ((len+2)/3)*4;
   for (i=0; i<len; ++i) {
     temp<<=8; temp+=s[i]; bits+=8;
     while (bits>6) {
-      if (dest) dest[written]=base64[((temp>>(bits-6))&63)];
+      dest[written]=base64[((temp>>(bits-6))&63)];
       ++written; bits-=6;
     }
   }
   if (bits) {
     temp<<=(6-bits);
-    if (dest) dest[written]=base64[temp&63];
+    dest[written]=base64[temp&63];
     ++written;
   }
-  while (written&3) { if (dest) dest[written]='='; ++written; }
+  while (written&3) { dest[written]='='; ++written; }
   return written;
 }