 FastTreeUPGMA-2.1.8.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/FastTreeUPGMA-2.1.8.c b/FastTreeUPGMA-2.1.8.c
index af76cb1..4065f42 100644
--- a/FastTreeUPGMA-2.1.8.c
+++ b/FastTreeUPGMA-2.1.8.c
@@ -535,7 +535,7 @@ int main(int argc, char **argv) {
       break;
   }
   if(iArg < argc-1) {
-    fprintf(stderr, usage);
+    fprintf(stderr, "%s", usage);
     exit(1);
   }
 
@@ -953,7 +953,7 @@ void PrintUPGMA(FILE *fp, UPGMA_t *UPGMA, char **names,
       assert(first >= 0);
       /* Print the name, or the subtree of duplicate names */
       if (nameNext[first] == -1) {
-	fprintf(fp, names[uniqueFirst[node]]);
+	fprintf(fp, "%s", names[uniqueFirst[node]]);
       } else {
 	fprintf(fp,"(%s:0.0",names[first]);
 	int iName = nameNext[first];
