diff --git a/pkgs/servers/sql/postgresql/generic.nix b/pkgs/servers/sql/postgresql/generic.nix
index a6bbe3871dc3a5..1810acef6897fe 100644
--- a/pkgs/servers/sql/postgresql/generic.nix
+++ b/pkgs/servers/sql/postgresql/generic.nix
@@ -380,10 +380,19 @@ let
             --replace-fail '-bundle_loader $(bindir)/postgres' "-bundle_loader $out/bin/postgres"
         '';
 
-      postFixup = lib.optionalString stdenv'.hostPlatform.isGnu ''
-        # initdb needs access to "locale" command from glibc.
-        wrapProgram $out/bin/initdb --prefix PATH ":" ${glibc.bin}/bin
-      '';
+      postFixup =
+        lib.optionalString stdenv'.hostPlatform.isGnu ''
+          # initdb needs access to "locale" command from glibc.
+          wrapProgram $out/bin/initdb --prefix PATH ":" ${glibc.bin}/bin
+        ''
+        + lib.optionalString pythonSupport (
+          let
+            pythonPath = "${python3}/lib/python${python3.sourceVersion.major}.${python3.sourceVersion.minor}/site-packages";
+          in
+          ''
+            wrapProgram "$out/bin/postgres" --set PYTHONPATH "${pythonPath}"
+          ''
+        );
 
       # Running tests as "install check" to work around SIP issue on macOS:
       # https://www.postgresql.org/message-id/flat/4D8E1BC5-BBCF-4B19-8226-359201EA8305%40gmail.com