diff --git a/pyproject.toml b/pyproject.toml
index 52e2a2f..b938464 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,10 +1,9 @@
 [build-system]
-requires = ["maturin"]
+requires = ["maturin>=1.0,<2"]
 build-backend = "maturin"
 
 [project]
 name = "rusty-rlp"
-version = "0.4.0"
 classifiers = [
   "Intended Audience :: Developers",
   "Programming Language :: Rust",
diff --git a/requirements-dev.txt b/requirements-dev.txt
index 8b5609c..0306757 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -1,4 +1,4 @@
-pytest==7.0.*
-maturin==1.4.*
-eth-utils==3.0.*
-rlp==4.0.*
+pytest
+maturin
+eth-utils
+rlp