diff --git a/pallas/Cargo.toml b/pallas/Cargo.toml
index ab299cd..eab47c3 100644
--- a/pallas/Cargo.toml
+++ b/pallas/Cargo.toml
@@ -26,4 +26,4 @@ pallas-hardano = { version = "=0.20.0", path = "../pallas-hardano/", optional =
 pallas-txbuilder = { version = "=0.20.0", path = "../pallas-txbuilder/", optional = true }
 
 [features]
-unstable = ["pallas-rolldb", "pallas-wallet", "pallas-hardano"]
+unstable = ["pallas-rolldb", "pallas-wallet", "pallas-hardano", "pallas-txbuilder"]