diff --git a/c-programming/jokes/extol.c b/c-programming/jokes/extol.c
index 22aa094..5074486 100644
--- a/c-programming/jokes/extol.c
+++ b/c-programming/jokes/extol.c
@@ -31,7 +31,12 @@ extol (FILE *f)
 
   if (f == NULL)
     {
-      FILE *fs = fopen ("extol.txt", "a+");
+      FILE *fs = fopen (EXTOL_FILE_NAME, "a+");
+      if (fs == NULL)
+        {
+          perror ("fopen");
+          exit (EXIT_FAILURE);
+        }
       fseek (fs, 0L, SEEK_END);
       result = extol (fs);
       for (result <<= 4, result &= ~15; (result & 15) != 15; result++)