diff --git a/nix/postgres/default.nix b/nix/postgres/default.nix
index e479c21..6190801 100644
--- a/nix/postgres/default.nix
+++ b/nix/postgres/default.nix
@@ -230,6 +230,24 @@ in
       '';
     };
 
+    depends_on = lib.mkOption {
+      description = "Extra process dependency relationships for `${name}-init` process.";
+      type = types.nullOr (types.attrsOf (types.submodule {
+        options = {
+          condition = lib.mkOption {
+            type = types.enum [
+              "process_completed"
+              "process_completed_successfully"
+              "process_healthy"
+              "process_started"
+            ];
+            example = "process_healthy";
+          };
+        };
+      }));
+      default = null;
+    };
+
     initialDumps = lib.mkOption {
       type = types.listOf types.path;
       default = [ ];
@@ -290,6 +308,7 @@ in
               in
               {
                 command = setupScript;
+                depends_on = config.depends_on;
                 namespace = name;
               };