diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index 7855ab2670d..e407a27d990 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -20067,11 +20067,18 @@ in {
 
     buildInputs = [ pkgs.libev ];
 
-    postPatch = ''
-      libev_so=${pkgs.libev}/lib/libev.so.4
-      test -f "$libev_so" || { echo "ERROR: File $libev_so does not exist, please fix nix expression for pyev"; exit 1; }
-      sed -i -e "s|libev_dll_name = find_library(\"ev\")|libev_dll_name = \"$libev_so\"|" setup.py
-    '';
+    postPatch =
+      if !stdenv.isDarwin 
+      then ''
+        libev_so=${pkgs.libev}/lib/libev.so.4
+        test -f "$libev_so" || { echo "ERROR: File $libev_so does not exist, please fix nix expression for pyev"; exit 1; }
+        sed -i -e "s|libev_dll_name = find_library(\"ev\")|libev_dll_name = \"$libev_so\"|" setup.py
+      ''
+      else ''
+        libev_so=${pkgs.libev}/lib/libev.4.dylib
+        test -f "$libev_so" || { echo "ERROR: File $libev_so does not exist, please fix nix expression for pyev"; exit 1; }
+        sed -i -e "s|libev_dll_name = find_library(\"ev\")|libev_dll_name = \"$libev_so\"|" setup.py
+      '';
 
     meta = {
       description = "Python bindings for libev";