diff --git a/src/args.rs b/src/args.rs
index fbbdbeb..dc8d9fe 100644
--- a/src/args.rs
+++ b/src/args.rs
@@ -80,7 +80,8 @@ pub struct RgaArgs {
     #[structopt(
         long = "--rga-cache-max-blob-len",
         default_value = "2000000",
-        hidden_short_help = true
+        hidden_short_help = true,
+        require_equals = true
     )]
     /// Max compressed size to cache
     ///