diff --git a/c/utils.c b/c/utils.c
index 2d685840f..1b52ba603 100644
--- a/c/utils.c
+++ b/c/utils.c
@@ -150,7 +150,7 @@ int indexOfString(const char *sourceString, size_t sourceLength, const char *sea
   const char * currPos = sourceString + startPos;
   const char * endPos = sourceString + sourceLength - searchLength;
   char firstChar = searchString[0];
-  while (currPos < endPos) {
+  while (currPos <= endPos) {
     size_t bytesRemaining = endPos - currPos + 1;
     currPos = memchr(currPos, firstChar, bytesRemaining);
     if (currPos == NULL) break;