diff --git a/pyproject.toml b/pyproject.toml
index 09b1373..2db000b 100755
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "novelai-python"
-version = "0.4.15"
+version = "0.4.16"
 description = "NovelAI Python Binding With Pydantic"
 authors = [
     { name = "sudoskys", email = "coldlando@hotmail.com" },
diff --git a/src/novelai_python/sdk/ai/generate_image/__init__.py b/src/novelai_python/sdk/ai/generate_image/__init__.py
index 5ebb269..1fe7b76 100755
--- a/src/novelai_python/sdk/ai/generate_image/__init__.py
+++ b/src/novelai_python/sdk/ai/generate_image/__init__.py
@@ -336,12 +336,18 @@ def model_post_init(self, *args) -> None:
         :param args: Any
         :return: None
         """
+        # Must be a string
         if self.parameters.negative_prompt is None:
             self.parameters.negative_prompt = ""
-        default_negative_prompt = get_default_uc_preset(self.model, self.parameters.ucPreset)
-        self.parameters.negative_prompt = ", ".join(
-            filter(None, [default_negative_prompt, self.parameters.negative_prompt])
-        )
+
+        # Add negative prompt based on ucPreset
+        if self.parameters.ucPreset is not None:
+            default_negative_prompt = get_default_uc_preset(self.model, self.parameters.ucPreset)
+            self.parameters.negative_prompt = ", ".join(
+                filter(None, [default_negative_prompt, self.parameters.negative_prompt])
+            )
+
+        # Add quality prompt
         if self.parameters.qualityToggle:
             self.input += ", best quality, amazing quality, very aesthetic, absurdres"