diff --git a/deployment/data-model-test.nix b/deployment/data-model-test.nix
index 97531fe8..1978be34 100644
--- a/deployment/data-model-test.nix
+++ b/deployment/data-model-test.nix
@@ -182,6 +182,7 @@ in
           };
         deployment = {
           inherit (result) _type;
+          isModule = lib.isFunction fediversity.deployments.example.deployment;
           deploymentFunction = lib.isFunction result.deploymentFunction;
           getProviders = lib.isFunction result.getProviders;
         };
@@ -204,6 +205,7 @@ in
         _type = "nixops4Deployment";
         deploymentFunction = true;
         getProviders = true;
+        isModule = false;
       };
     };
   };
diff --git a/deployment/data-model.nix b/deployment/data-model.nix
index b3a62b32..0bec8ad4 100644
--- a/deployment/data-model.nix
+++ b/deployment/data-model.nix
@@ -142,7 +142,7 @@ in
             resource-mapping = mkOption {
               description = "Function type for the mapping from resources to a (NixOps4) deployment";
               type = functionType;
-              readOnly = true;
+              # readOnly = true;
               default = {
                 input-type = application-resources;
                 output-type = nixops4Deployment;
diff --git a/deployment/function.nix b/deployment/function.nix
index 69241925..7c66f9ce 100644
--- a/deployment/function.nix
+++ b/deployment/function.nix
@@ -20,7 +20,7 @@ submodule (function: {
     };
     function-type = mkOption {
       type = optionType;
-      readOnly = true;
+      # readOnly = true;
       default = functionTo (submodule {
         options = {
           input = mkOption {