diff --git a/portproton/preinstall.sh b/portproton/preinstall.sh
index 38f72e6..c440473 100644
--- a/portproton/preinstall.sh
+++ b/portproton/preinstall.sh
@@ -1,5 +1,5 @@
 #!/usr/bin/env bash
-if grep -q ID=debian "/etc/os-release"; then
+if [grep -q ID=debian "/etc/os-release"]; then
 sudo dpkg --add-architecture i386
 sudo apt-get update
 fi