diff --git a/bin/install b/bin/install
index d2615c6..02a56ae 100644
--- a/bin/install
+++ b/bin/install
@@ -10,7 +10,7 @@ install_php() {
     if [ "$TMPDIR" = "" ]; then
         local tmp_download_dir=$(mktemp -d)
     else
-        local tmp_download_dir=$TMPDIR
+        local tmp_download_dir=${TMPDIR%/}
     fi
 
     local source_path=$(get_download_file_path $install_type $version $tmp_download_dir)