diff --git a/thirdparty/build-redis.sh b/thirdparty/build-redis.sh
index 57c68c97b..230e9ae29 100644
--- a/thirdparty/build-redis.sh
+++ b/thirdparty/build-redis.sh
@@ -1,4 +1,6 @@
-wget http://download.redis.io/releases/redis-3.2.3.tar.gz
-tar xvfz redis-3.2.3.tar.gz
-cd redis-3.2.3
-make
+if [ ! -f redis-3.2.3/src/redis-server ]; then
+  wget http://download.redis.io/releases/redis-3.2.3.tar.gz
+  tar xvfz redis-3.2.3.tar.gz
+  cd redis-3.2.3
+  make
+fi