diff --git a/libs/libc/time/lib_localtime.c b/libs/libc/time/lib_localtime.c
index 5058a8d2e2..0f981b08d3 100644
--- a/libs/libc/time/lib_localtime.c
+++ b/libs/libc/time/lib_localtime.c
@@ -461,7 +461,7 @@ static int_fast64_t detzcode64(FAR const char *codep)
   result = (codep[0] & 0x80) ? -1 : 0;
   for (i = 0; i < 8; ++i)
     {
-      result = (result << 8) | (codep[i] & 0xff);
+      result = (result * 256) | (codep[i] & 0xff);
     }
 
   return result;