diff --git a/kalk/Cargo.toml b/kalk/Cargo.toml
index 99915ea..1d00a9c 100644
--- a/kalk/Cargo.toml
+++ b/kalk/Cargo.toml
@@ -19,4 +19,9 @@ 
 wasm-bindgen = "0.2.69"
+
+[dependencies.gmp-mpfr-sys]
+version = "1.6.2"
+default-features = false
+features = ["mpfr", "use-system-libs"]

 [dev-dependencies]
 wasm-bindgen-test = "0.3.19"