diff --git a/build.sh b/build.sh
index 965f3484fa29ef45475c776a13b0b312ef0ff5de..d58e92b57bb1be8173c155248a926de75fabda52 100755
--- a/build.sh
+++ b/build.sh
@@ -2,7 +2,7 @@
 #
 # for windows and Mac check the README
 #
-BIN_NAME=acme-downloader.exe
+BIN_NAME=acme-downloader
 PATH=$PATH:$(go env GOPATH)/bin
 GOPATH=$(go env GOPATH)
 PROG_VERSION="1.0"
@@ -57,6 +57,10 @@ if [ -z $PLATFORM -o -z $ARCH ]; then
     usage
 fi
 
+if [ "$PLATFORM" == "windows" ]; then
+    $BIN_NAME = "${BIN_NAME}.exe"
+fi
+
 EXECUTABLE_PATH="${GOPATH}/bin/${PLATFORM}_${ARCH}/${BIN_NAME}"
 
 run_upx() {