diff --git a/pkgs/development/python-modules/trio/default.nix b/pkgs/development/python-modules/trio/default.nix
index e667f146afc..f9b325ecc29 100644
--- a/pkgs/development/python-modules/trio/default.nix
+++ b/pkgs/development/python-modules/trio/default.nix
@@ -13,19 +13,45 @@
 , jedi
 , astor
 , yapf
+, coreutils
 }:
 
 buildPythonPackage rec {
   pname = "trio";
-  version = "0.19.0";
+  version = "0.20.0";
   disabled = pythonOlder "3.6";
 
   src = fetchPypi {
     inherit pname version;
-    sha256 = "895e318e5ec5e8cea9f60b473b6edb95b215e82d99556a03eb2d20c5e027efe1";
+    sha256 = "sha256-ZwpS0xFdDoeeGsg4pOuZmvMvhYFj46cE/kg53ipnYHA=";
   };
 
-  checkInputs = [ astor pytestCheckHook pyopenssl trustme jedi yapf ];
+  propagatedBuildInputs = [
+    attrs
+    sortedcontainers
+    async_generator
+    idna
+    outcome
+    sniffio
+  ] ++ lib.optionals (pythonOlder "3.7") [ contextvars ];
+
+  # tests are failing on Darwin
+  doCheck = !stdenv.isDarwin;
+
+  checkInputs = [
+    astor
+    jedi
+    pyopenssl
+    pytestCheckHook
+    trustme
+    yapf
+  ];
+
+  preCheck = ''
+    substituteInPlace trio/tests/test_subprocess.py \
+      --replace "/bin/sleep" "${coreutils}/bin/sleep"
+  '';
+
   # It appears that the build sandbox doesn't include /etc/services, and these tests try to use it.
   disabledTests = [
     "getnameinfo"
@@ -41,18 +67,6 @@ buildPythonPackage rec {
     "-W" "ignore::DeprecationWarning"
   ];
 
-  propagatedBuildInputs = [
-    attrs
-    sortedcontainers
-    async_generator
-    idna
-    outcome
-    sniffio
-  ] ++ lib.optionals (pythonOlder "3.7") [ contextvars ];
-
-  # tests are failing on Darwin
-  doCheck = !stdenv.isDarwin;
-
   meta = {
     description = "An async/await-native I/O library for humans and snake people";
     homepage = "https://github.com/python-trio/trio";
diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index a2775766e1d..765a5e31724 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -10084,7 +10084,9 @@ in {
 
   trimesh = callPackage ../development/python-modules/trimesh { };
 
-  trio = callPackage ../development/python-modules/trio { };
+  trio = callPackage ../development/python-modules/trio {
+    inherit (pkgs) coreutils;
+  };
 
   trio-asyncio = callPackage ../development/python-modules/trio-asyncio { };