diff --git a/pkgs/development/python-modules/exif/default.nix b/pkgs/development/python-modules/exif/default.nix
index 2c549030e6d7..da4ba40a9246 100644
--- a/pkgs/development/python-modules/exif/default.nix
+++ b/pkgs/development/python-modules/exif/default.nix
@@ -2,25 +2,22 @@
 
 buildPythonPackage rec {
   pname = "exif";
-  version = "1.2.0";
+  version = "1.3.5";
   disabled = !isPy3k;
 
   src = fetchFromGitLab {
     owner = "TNThieding";
     repo = "exif";
-    rev = "686857c677f489759db90b1ad61fa1cc1cac5f9a";
-    sha256 = "0z2if23kmi0iyxviz32mlqs997i3dqpqfz6nznlwkhkkb6rkwwnh";
+    rev = "v${version}";
+    sha256 = "sha256-XSORawioXo8oPVZ3Jnxqa6GFIxnQZMT0vJitdmpBj0E=";
   };
 
   propagatedBuildInputs = [ plum-py ];
 
-  postPatch = ''
-    substituteInPlace setup.py \
-      --replace "plum-py==0.3.1" "plum-py>=0.3.1"
-  '';
-
   checkInputs = [ pytestCheckHook baseline ];
 
+  pythonImportsCheck = [ "exif" ];
+
   meta = with lib; {
     description = "Read and modify image EXIF metadata using Python";
     homepage    = "https://gitlab.com/TNThieding/exif";
diff --git a/pkgs/development/python-modules/plum-py/default.nix b/pkgs/development/python-modules/plum-py/default.nix
index 50a33266c8fa..5b963cbfef4e 100644
--- a/pkgs/development/python-modules/plum-py/default.nix
+++ b/pkgs/development/python-modules/plum-py/default.nix
@@ -2,20 +2,17 @@
 
 buildPythonPackage rec {
   pname = "plum-py";
-  version = "0.4.0";
+  version = "0.8.5";
   disabled = !isPy3k;
 
   src = fetchFromGitLab {
     owner = "dangass";
     repo = "plum";
-    rev = "6a9ff863c0e9fa21f7b2230d25402155a5522e4b";
-    sha256 = "1iv62yb704c61b0dvsmyp3j6xpbmay532g9ny4pw4zbg3l69vd5j";
+    rev = version;
+    sha256 = "sha256-jCZUNT1HpSr0khHsjnxEzN2LCzcDV6W27PjVkwFJHUg=";
   };
 
-  postPatch = ''
-    substituteInPlace src/plum/int/flag/_flag.py \
-      --replace 'if sys.version_info < (3, 7):' 'if True:'
-  '';
+  pythonImportsCheck = [ "plum" ];
 
   checkInputs = [ pytest baseline ];
   checkPhase = "pytest tests";