diff --git a/source/blender/blenkernel/intern/node_tree_field_inferencing.cc b/source/blender/blenkernel/intern/node_tree_field_inferencing.cc
index 0413e28a297..82e425dfbb9 100644
--- a/source/blender/blenkernel/intern/node_tree_field_inferencing.cc
+++ b/source/blender/blenkernel/intern/node_tree_field_inferencing.cc
@@ -56,13 +56,6 @@ static InputSocketFieldType get_interface_input_field_type(const bNode &node,
   /* Get the field type from the declaration. */
   const SocketDeclaration &socket_decl = *node_decl->inputs()[socket.index()];
   const InputSocketFieldType field_type = socket_decl.input_field_type();
-  if (field_type == InputSocketFieldType::Implicit) {
-    return field_type;
-  }
-  if (node_decl->is_function_node()) {
-    /* In a function node, every socket supports fields. */
-    return InputSocketFieldType::IsSupported;
-  }
   return field_type;
 }
 
@@ -93,11 +86,6 @@ static OutputFieldDependency get_interface_output_field_dependency(const bNode &
   /* Node declarations should be implemented for nodes involved here. */
   BLI_assert(node_decl != nullptr);
 
-  if (node_decl->is_function_node()) {
-    /* In a generic function node, all outputs depend on all inputs. */
-    return OutputFieldDependency::ForDependentField();
-  }
-
   /* Use the socket declaration. */
   const SocketDeclaration &socket_decl = *node_decl->outputs()[socket.index()];
   return socket_decl.output_field_dependency();
diff --git a/source/blender/nodes/NOD_node_declaration.hh b/source/blender/nodes/NOD_node_declaration.hh
index b06f0736917..975cc96131c 100644
--- a/source/blender/nodes/NOD_node_declaration.hh
+++ b/source/blender/nodes/NOD_node_declaration.hh
@@ -309,7 +309,6 @@ class NodeDeclaration {
  private:
   Vector<SocketDeclarationPtr> inputs_;
   Vector<SocketDeclarationPtr> outputs_;
-  bool is_function_node_ = false;
 
   friend NodeDeclarationBuilder;
 
@@ -320,11 +319,6 @@ class NodeDeclaration {
   Span<SocketDeclarationPtr> outputs() const;
   Span<SocketDeclarationPtr> sockets(eNodeSocketInOut in_out) const;
 
-  bool is_function_node() const
-  {
-    return is_function_node_;
-  }
-
   MEM_CXX_CLASS_ALLOC_FUNCS("NodeDeclaration")
 };
 
@@ -332,22 +326,22 @@ class NodeDeclarationBuilder {
  private:
   NodeDeclaration &declaration_;
   Vector<std::unique_ptr<BaseSocketDeclarationBuilder>> builders_;
+  bool is_function_node_ = false;
 
  public:
   NodeDeclarationBuilder(NodeDeclaration &declaration);
 
   /**
    * All inputs support fields, and all outputs are fields if any of the inputs is a field.
-   * Calling field status definitions on each socket is unnecessary. Must be called before adding
-   * any sockets.
+   * Calling field status definitions on each socket is unnecessary.
    */
-  void is_function_node(bool value = true)
+  void is_function_node()
   {
-    BLI_assert_msg(declaration_.inputs().is_empty() && declaration_.outputs().is_empty(),
-                   "is_function_node() must be called before any socket is created");
-    declaration_.is_function_node_ = value;
+    is_function_node_ = true;
   }
 
+  void finalize();
+
   template<typename DeclType>
   typename DeclType::Builder &add_input(StringRef name, StringRef identifier = "");
   template<typename DeclType>
@@ -553,10 +547,6 @@ inline typename DeclType::Builder &NodeDeclarationBuilder::add_socket(StringRef
   socket_decl->name_ = name;
   socket_decl->identifier_ = identifier.is_empty() ? name : identifier;
   socket_decl->in_out_ = in_out;
-  if (declaration_.is_function_node()) {
-    socket_decl->input_field_type_ = InputSocketFieldType::IsSupported;
-    socket_decl->output_field_dependency_ = OutputFieldDependency::ForDependentField();
-  }
   declarations.append(std::move(socket_decl));
   Builder &socket_decl_builder_ref = *socket_decl_builder;
   builders_.append(std::move(socket_decl_builder));
diff --git a/source/blender/nodes/intern/node_declaration.cc b/source/blender/nodes/intern/node_declaration.cc
index 7a6e237a18f..0811bfeb516 100644
--- a/source/blender/nodes/intern/node_declaration.cc
+++ b/source/blender/nodes/intern/node_declaration.cc
@@ -11,6 +11,21 @@ void build_node_declaration(const bNodeType &typeinfo, NodeDeclaration &r_declar
 {
   NodeDeclarationBuilder node_decl_builder{r_declaration};
   typeinfo.declare(node_decl_builder);
+  node_decl_builder.finalize();
+}
+
+void NodeDeclarationBuilder::finalize()
+{
+  if (is_function_node_) {
+    for (SocketDeclarationPtr &socket_decl : declaration_.inputs_) {
+      if (socket_decl->input_field_type_ != InputSocketFieldType::Implicit) {
+        socket_decl->input_field_type_ = InputSocketFieldType::IsSupported;
+      }
+    }
+    for (SocketDeclarationPtr &socket_decl : declaration_.outputs_) {
+      socket_decl->output_field_dependency_ = OutputFieldDependency::ForDependentField();
+    }
+  }
 }
 
 bool NodeDeclaration::matches(const bNode &node) const