diff --git a/dbterd/adapters/targets/mermaid.py b/dbterd/adapters/targets/mermaid.py
index 5f3ef51..443e140 100644
--- a/dbterd/adapters/targets/mermaid.py
+++ b/dbterd/adapters/targets/mermaid.py
@@ -42,7 +42,7 @@ def match_complex_column_type(column_type: str) -> Optional[str]:
     Returns:
         Optional[str]: Returns root type if input type is nested complex type, otherwise returns `None` for primitive types
     """
-    pattern = r"(\w+)<(\w+\s+\w+(\s*,\s*\w+\s+\w+)*)>"
+    pattern = r"(\w+)<.*>"
     match = re.match(pattern, column_type)
     if match:
         return match.group(1)
diff --git a/tests/unit/adapters/targets/mermaid/test_mermaid_column_types.py b/tests/unit/adapters/targets/mermaid/test_mermaid_column_types.py
new file mode 100644
index 0000000..4fcd089
--- /dev/null
+++ b/tests/unit/adapters/targets/mermaid/test_mermaid_column_types.py
@@ -0,0 +1,26 @@
+import pytest
+
+from dbterd.adapters.targets import mermaid
+
+complex_column_types = [
+    ("string", None),
+    ("struct<string a, string b>", "struct"),
+    ("array<struct<string a, string b>>", "array"),
+    ("array<struct<string a_id, string b_id>>", "array"),
+]
+column_types = [
+    ("string", "string"),
+    ("struct<string a, string b>", "struct[OMITTED]"),
+    ("array<struct<string a, string b>>", "array[OMITTED]"),
+    ("array<struct<string a_id, string b_id>>", "array[OMITTED]"),
+]
+
+
+@pytest.mark.parametrize("input,expected", complex_column_types)
+def test_match_complex_column_type(input, expected):
+    assert mermaid.match_complex_column_type(input) == expected
+
+
+@pytest.mark.parametrize("input,expected", column_types)
+def test_replace_column_type(input, expected):
+    assert mermaid.replace_column_type(input) == expected