diff --git a/pkgs/applications/office/paperless/default.nix b/pkgs/applications/office/paperless/default.nix
index af2fd82ddb03..97088f360417 100644
--- a/pkgs/applications/office/paperless/default.nix
+++ b/pkgs/applications/office/paperless/default.nix
@@ -57,6 +57,12 @@ let
       cp -r --no-preserve=mode $src/src/* $src/LICENSE $srcDir
     '';
 
+    postPatch = ''
+      # django-cors-headers 3.x requires a scheme for allowed hosts
+      substituteInPlace $out/share/paperless/paperless/settings.py \
+        --replace "localhost:8080" "http://localhost:8080"
+    '';
+
     buildPhase = let
       # Paperless has explicit runtime checks that expect these binaries to be in PATH
       extraBin = lib.makeBinPath [ imagemagick7 ghostscript optipng tesseract unpaper ];
diff --git a/pkgs/applications/office/paperless/python-modules/django-crispy-forms.nix b/pkgs/applications/office/paperless/python-modules/django-crispy-forms.nix
index c1e0f7da30f6..465da3862471 100644
--- a/pkgs/applications/office/paperless/python-modules/django-crispy-forms.nix
+++ b/pkgs/applications/office/paperless/python-modules/django-crispy-forms.nix
@@ -1,5 +1,5 @@
 { lib, buildPythonPackage, fetchFromGitHub
-, pytest, pytest-django, django }:
+, pytest_4, pytest-django, django }:
 
 buildPythonPackage {
   pname = "django-crispy-forms";
@@ -19,7 +19,7 @@ buildPythonPackage {
     export sourceRoot=source-
   '';
 
-  checkInputs = [ pytest pytest-django django ];
+  checkInputs = [ pytest_4 pytest-django django ];
 
   checkPhase = ''
     PYTHONPATH="$(pwd):$PYTHONPATH" \
diff --git a/pkgs/development/python-modules/pytest/2.nix b/pkgs/development/python-modules/pytest/4.nix
similarity index 100%
rename from pkgs/development/python-modules/pytest/2.nix
rename to pkgs/development/python-modules/pytest/4.nix
diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index 96885a83ebb4..62901ef20520 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -1991,15 +1991,17 @@ in {
 
   pyhepmc = callPackage ../development/python-modules/pyhepmc { };
 
-  pytest = if isPy3k then
-    callPackage ../development/python-modules/pytest {
-      # hypothesis tests require pytest that causes dependency cycle
-      hypothesis = self.hypothesis.override { doCheck = false; };
-    }
-  else callPackage ../development/python-modules/pytest/2.nix {
-      # hypothesis tests require pytest that causes dependency cycle
-      hypothesis = self.hypothesis.override { doCheck = false; };
-    };
+  pytest = if isPy3k then self.pytest_5 else self.pytest_4;
+
+  pytest_5 = callPackage ../development/python-modules/pytest {
+    # hypothesis tests require pytest that causes dependency cycle
+    hypothesis = self.hypothesis.override { doCheck = false; };
+  };
+
+  pytest_4 = callPackage ../development/python-modules/pytest/4.nix {
+    # hypothesis tests require pytest that causes dependency cycle
+    hypothesis = self.hypothesis.override { doCheck = false; };
+  };
 
   pytest-helpers-namespace = callPackage ../development/python-modules/pytest-helpers-namespace { };