diff -Naur libpuffy-1.0/fmt_scaled.c libpuffy-1.0.serenity/fmt_scaled.c
--- libpuffy-1.0/fmt_scaled.c	2020-03-14 21:04:34.000000000 +0100
+++ libpuffy-1.0.serenity/fmt_scaled.c	2021-05-01 22:39:53.429380002 +0200
@@ -207,11 +207,13 @@
 	return -1;
 }
 
+#ifndef __serenity__
 static long long
 llabs(long long j)
 {
 	return (j < 0 ? -j : j);
 }
+#endif
 
 /* Format the given "number" into human-readable form in "result".
  * Result must point to an allocated buffer of length FMT_SCALED_STRSIZE.