diff --git a/nixos/modules/services/databases/postgresql.nix b/nixos/modules/services/databases/postgresql.nix
index a7016bbee3a86..1c16a5007291c 100644
--- a/nixos/modules/services/databases/postgresql.nix
+++ b/nixos/modules/services/databases/postgresql.nix
@@ -69,6 +69,15 @@ in
         '';
       };
 
+      socketDir = mkOption {
+        type = with types; nullOr path;
+        default = /run/postgresql;
+        description = lib.mdDoc ''
+          Directory where PostgreSQL opens a UNIX domain socket to which clients can connect.
+          A null value opens no socket, leaving PostgreSQL accessible only via TCP/IP.
+        '';
+      };
+
       checkConfig = mkOption {
         type = types.bool;
         default = true;
@@ -446,6 +455,7 @@ in
         log_line_prefix = cfg.logLinePrefix;
         listen_addresses = if cfg.enableTCPIP then "*" else "localhost";
         port = cfg.port;
+        unix_socket_directories = toString cfg.socketDir;
         jit = mkDefault (if cfg.enableJIT then "on" else "off");
       };
 
@@ -522,9 +532,10 @@ in
           '';
 
         # Wait for PostgreSQL to be ready to accept connections.
-        postStart =
-          ''
-            PSQL="psql --port=${toString cfg.port}"
+        postStart = let
+          host = if (cfg.socketDir == null) then "" else "--host=${toString cfg.socketDir}";
+          in ''
+            PSQL="psql --port=${toString cfg.port} ${host}"
 
             while ! $PSQL -d postgres -c "" 2> /dev/null; do
                 if ! kill -0 "$MAINPID"; then exit 1; fi