diff --git a/generate.c b/generate.c
index cdbdd70..3a14d6d 100644
--- a/generate.c
+++ b/generate.c
@@ -21,9 +21,11 @@ static char* alphabetize(weylgroup_element_t *e, char *str)
 {
   if(e->wordlength == 0)
     sprintf(str, "1");
-  else
+  else {
     for(int j = 0; j < e->wordlength; j++)
-      sprintf(str, "%c", e->word[j] + 'a');
+      str[j] = e->word[j] + 'a';
+    str[e->wordlength] = 0;
+  }
 
   return str;
 }