diff --git a/c/isogram/src/isogram.c b/c/isogram/src/isogram.c
index a20852c..b9a161b 100644
--- a/c/isogram/src/isogram.c
+++ b/c/isogram/src/isogram.c
@@ -4,7 +4,7 @@
 int length(const char string[]) {
   int i = 0;
   while (string[i] != '\0') { i++; }
-  return i+1; // Account for terminating null char.
+  return i;
 }
 
 char lowercase(char c) {