diff --git a/msort.c b/msort.c
index 7187ed4..e21f5dd 100644
--- a/msort.c
+++ b/msort.c
@@ -2133,7 +2133,7 @@ DescribeKeys(FILE *fp)
 	else if(first %  10 == 2) sprintf(tmp,"%dnd field from end",first);
 	else sprintf(tmp,"%dth field from end",first);
       }
-      fprintf(fp,tmp);
+      fprintf(fp,"%s", tmp);
       if (KeyInfo[i]->FirstOffset > 0) {
 	fprintf(fp," character %d",(KeyInfo[i]->FirstOffset)+1);
       }
@@ -2165,7 +2165,7 @@ DescribeKeys(FILE *fp)
 	  else if(last %  10 == 2) sprintf(tmp,"%dnd field from end",last);
 	  else sprintf(tmp,"%dth field from end",last);
 	}
-	fprintf(fp,tmp);
+	fprintf(fp,"%s", tmp);
 	if (KeyInfo[i]->LastOffset > 0) {
 	  fprintf(fp," character %d",(KeyInfo[i]->LastOffset)+1);
 	}