diff --git a/pkgs/by-name/op/openvswitch/package.nix b/pkgs/by-name/op/openvswitch/package.nix
index 465312a8ab0b..f21df7e9b0d4 100644
--- a/pkgs/by-name/op/openvswitch/package.nix
+++ b/pkgs/by-name/op/openvswitch/package.nix
@@ -102,8 +102,8 @@ stdenv.mkDerivation rec {
   postInstall = ''
     # Install bash completions in correct location
     rm -f $out/etc/bash_completion.d/ovs-*.bash
-    installShellCompletion --bash utilities/ovs-appctl-bashcomp.bash
-    installShellCompletion --bash utilities/ovs-vsctl-bashcomp.bash
+    installShellCompletion utilities/ovs-appctl-bashcomp.bash
+    installShellCompletion utilities/ovs-vsctl-bashcomp.bash
 
     mkdir -p $tools/{bin,share/openvswitch/scripts}
     mv $out/share/openvswitch/bugtool-plugins $tools/share/openvswitch