diff --git a/gaboshlib/g_percentage-diff.bashfunc b/gaboshlib/g_percentage-diff.bashfunc
index f97a3d3..14108df 100644
--- a/gaboshlib/g_percentage-diff.bashfunc
+++ b/gaboshlib/g_percentage-diff.bashfunc
@@ -3,5 +3,5 @@
 function g_percentage-diff {
   local g_from=$1
   local g_to=$2
-  printf -- "%.2f" $(g_calc "100/$g_from*($g_to-$g_from)")
+  printf -- "%.2f" $(g_calc "100/${g_from}*(${g_to}-${g_from})")
 }