diff --git a/libbb/xfuncs.c b/libbb/xfuncs.c
index 140c7bb6f..2215bb8df 100644
--- a/libbb/xfuncs.c
+++ b/libbb/xfuncs.c
@@ -323,7 +323,8 @@ void smart_ulltoa5(unsigned long long ul, char buf[5])
 		}
 		buf[2] = "0123456789"[v];
 		// see http://en.wikipedia.org/wiki/Tera
-		buf[3] = " kMGTPEZY"[idx];
+		// (small letters stand out better versus numbers)
+		buf[3] = " kmgtpezy"[idx];
 	}
 	buf[4] = '\0';
 }