diff --git a/cmd/fpkg/install.go b/cmd/fpkg/install.go
index 47d4ffc..481dea1 100644
--- a/cmd/fpkg/install.go
+++ b/cmd/fpkg/install.go
@@ -163,6 +163,8 @@ func actionInstall(args []string) {
 		"rm -rf .local/state/{nix,home-manager}",
 		// run activation script
 		bundle.ActivationPackage + "/activate",
+		// deduplicate nix store
+		"nix store --offline optimise",
 	}, false, func(config *fst.Config) *fst.Config { return config }, bundle, pathSet, dropShellActivate, cleanup)
 
 	/*