diff --git a/tests/unit/test_llm_chat.py b/tests/unit/test_llm_chat.py
index 90bb483a..57a00d1d 100644
--- a/tests/unit/test_llm_chat.py
+++ b/tests/unit/test_llm_chat.py
@@ -408,6 +408,11 @@ def test_coerce_to_dict_or_list_valid_inputs(self):
         result = chat._coerce_to_dict_or_list(json_array)
         assert result == [{"name": "John"}, {"name": "Jane"}]
 
+        # Valid empty JSON object with whitespace
+        empty_json_object = "  { }\n"
+        result = chat._coerce_to_dict_or_list(empty_json_object)
+        assert result == {}
+
         # Already a dict
         dict_input = {"key": "value"}
         result = chat._coerce_to_dict_or_list(dict_input)
@@ -428,6 +433,15 @@ def test_coerce_to_dict_or_list_invalid_inputs(self):
         with pytest.raises(ValueError, match="Cannot convert"):
             chat._coerce_to_dict_or_list("42")  # valid JSON but not dict/list
 
+        for malformed_json in (
+            "[{[}]",
+            "{not json}",
+            'prefix {"name": } suffix',
+            "malformed {[}] followed by {}",
+        ):
+            with pytest.raises(ValueError, match="Cannot convert"):
+                chat._coerce_to_dict_or_list(malformed_json)
+
     def test_coerce_to_list_valid_inputs(self):
         """Test list coercion with valid inputs."""
         chat = LLMChat(system_prompt="Test", user_prompt="Test")
diff --git a/tinytroupe/utils/llm.py b/tinytroupe/utils/llm.py
index 0c265ce6..bc1ea3c3 100644
--- a/tinytroupe/utils/llm.py
+++ b/tinytroupe/utils/llm.py
@@ -933,7 +933,7 @@ def _coerce_to_dict_or_list(self, llm_output: str):
             # extract_json returns {} on failure, but we need dict or list
             if result == {} and not (
                 isinstance(llm_output, str)
-                and ("{}" in llm_output or "{" in llm_output and "}" in llm_output)
+                and re.fullmatch(r"\s*\{\s*\}\s*", llm_output)
             ):
                 raise ValueError(
                     "Cannot convert the LLM output to a dict or list value."