diff --git a/nixfig.go b/nixfig.go
index d89e98b..e1597bc 100644
--- a/nixfig.go
+++ b/nixfig.go
@@ -33,6 +33,9 @@ func init() {
 	}
 	if envPath, ok := os.LookupEnv("NIXFIG_FMT"); ok {
 		Fmt = strings.Split(envPath, " ")
+		if envPath == "" {
+			Fmt = nil
+		}
 	}
 }