diff --git a/default.nix b/default.nix
index 478e424e1..729568cfe 100644
--- a/default.nix
+++ b/default.nix
@@ -36,6 +36,7 @@ let
       allOverlays.build-toolbox
       allOverlays.checked-shell-script
       allOverlays.gitignore
+      allOverlays.postgis
       allOverlays.postgresql-default
       allOverlays.postgresql-legacy
       allOverlays.postgresql-future
diff --git a/nix/overlays/default.nix b/nix/overlays/default.nix
index 05480d5e5..43d154868 100644
--- a/nix/overlays/default.nix
+++ b/nix/overlays/default.nix
@@ -3,6 +3,7 @@
   checked-shell-script = import ./checked-shell-script;
   gitignore = import ./gitignore.nix;
   haskell-packages = import ./haskell-packages.nix;
+  postgis = import ./postgis.nix;
   postgresql-default = import ./postgresql-default.nix;
   postgresql-legacy = import ./postgresql-legacy.nix;
   postgresql-future = import ./postgresql-future.nix;
diff --git a/nix/overlays/postgis.nix b/nix/overlays/postgis.nix
new file mode 100644
index 000000000..846fb7a85
--- /dev/null
+++ b/nix/overlays/postgis.nix
@@ -0,0 +1,27 @@
+final: prev:
+let
+  postgis_3_2_3 = rec {
+    version = "3.2.3";
+    src = final.fetchurl {
+      url = "https://download.osgeo.org/postgis/source/postgis-${version}.tar.gz";
+      sha256 = "sha256-G02LXHVuWrpZ77wYM7Iu/k1lYneO7KVvpJf+susTZow=";
+    };
+  };
+in
+{
+  postgresql_11 = prev.postgresql_11.override { this = final.postgresql_11; } // {
+    pkgs = prev.postgresql_11.pkgs // {
+      postgis = prev.postgresql_11.pkgs.postgis.overrideAttrs (_: postgis_3_2_3);
+    };
+  };
+  postgresql_10 = prev.postgresql_10.override { this = final.postgresql_11; } // {
+    pkgs = prev.postgresql_10.pkgs // {
+      postgis = prev.postgresql_10.pkgs.postgis.overrideAttrs (_: postgis_3_2_3);
+    };
+  };
+  postgresql_9_6 = prev.postgresql_9_6.override { this = final.postgresql_11; } // {
+    pkgs = prev.postgresql_9_6.pkgs // {
+      postgis = prev.postgresql_9_6.pkgs.postgis.overrideAttrs (_: postgis_3_2_3);
+    };
+  };
+}