diff --git a/src/conky.cc b/src/conky.cc
index d55bff54..80b5fbef 100644
--- a/src/conky.cc
+++ b/src/conky.cc
@@ -746,7 +746,7 @@ void human_readable(long long num, char *buf, int size) {
   float fnum;
   int precision;
   int width;
-  const char *format;
+  static const char *const format = "%.*f%.1s";
 
   /* Possibly just output as usual, for example for stdout usage */
   if (!format_human_readable.get(*state)) {
@@ -755,10 +755,8 @@ void human_readable(long long num, char *buf, int size) {
   }
   if (short_units.get(*state)) {
     width = 5;
-    format = "%.*f%.1s";
   } else {
     width = 7;
-    format = "%.*f%-3s";
   }
 
   if (llabs(num) < 1000LL) {