diff --git a/pyproject.toml b/pyproject.toml
index 6710aef5f7805e917177741fe627a7cad53307d8..6eba2494e64ddd30b176cc8d9aaa581b48b51fa4 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -31,19 +31,18 @@ packages = [
 
 
 [tool.poetry.dependencies]
-python = "^3.5"
-numpy  = ">= 1.17"
+python = ">= 3.7, < 4"
+numpy  = ">= 1.19"
 
 
 [tool.poetry.dev-dependencies]
-pytest = { version = "^5.2", python = ">=3.5" }
-coverage = { version = ">= 6.3.2", python = ">=3.7" }
-sphinx = { version = ">= 4.4", python = ">=3.6" }
-sphinx-rtd-theme = { version = ">= 1.0", python = ">=2.7,!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*" }
-enum-tools = { version = ">=0.9", python = ">=3.6" }
-sphinx-toolbox = { version = ">= 2.16.0", python = ">=3.6.1" }
-black = { version = "^22.3.0", python = "^3.6.2" }
-numpy = { version = ">=1.22", python = ">=3.8" }
+pytest = "^5.2"
+coverage = ">= 6.3.2"
+sphinx = ">= 4.4"
+sphinx-rtd-theme = ">= 1.0"
+enum-tools = ">=0.9"
+sphinx-toolbox = ">= 2.16.0"
+black = "^22.3.0"
 
 
 [tool.black]