diff --git a/include/typings/pkpy.pyi b/include/typings/pkpy.pyi
index e6837216..36ed66d9 100644
--- a/include/typings/pkpy.pyi
+++ b/include/typings/pkpy.pyi
@@ -14,3 +14,6 @@ class TValue[T]:
 
 def memory_usage() -> str:
     """Return a summary of the memory usage."""
+
+def is_user_defined_type(t: type) -> bool:
+    """Check if a type is user-defined. This means the type was created by executing python `class` statement."""
\ No newline at end of file
diff --git a/src/modules/pkpy.c b/src/modules/pkpy.c
index 594fee47..f1a76c2f 100644
--- a/src/modules/pkpy.c
+++ b/src/modules/pkpy.c
@@ -55,6 +55,14 @@ static bool pkpy_memory_usage(int argc, py_Ref argv) {
     return true;
 }
 
+static bool pkpy_is_user_defined_type(int argc, py_Ref argv) {
+    PY_CHECK_ARGC(1);
+    PY_CHECK_ARG_TYPE(0, tp_type);
+    py_TypeInfo* ti = pk__type_info(py_totype(argv));
+    py_newbool(py_retval(), ti->is_python);
+    return true;
+}
+
 void pk__add_module_pkpy() {
     py_Ref mod = py_newmodule("pkpy");
 
@@ -90,6 +98,7 @@ void pk__add_module_pkpy() {
     py_pop();
 
     py_bindfunc(mod, "memory_usage", pkpy_memory_usage);
+    py_bindfunc(mod, "is_user_defined_type", pkpy_is_user_defined_type);
 }
 
 #undef DEF_TVALUE_METHODS
\ No newline at end of file
diff --git a/tests/91_pdb.py b/tests/91_pdb.py
deleted file mode 100644
index f60ef89d..00000000
--- a/tests/91_pdb.py
+++ /dev/null
@@ -1,19 +0,0 @@
-# a = 1
-# b = 2
-
-# print(a, b)
-
-
-# def f(a, b):
-#     b = a + b
-#     print(a, b)
-#     return b
-
-# def g(a, b):
-#     breakpoint()
-#     c = f(a, b)
-#     return c
-
-# g(1, 2)
-# f(3, 4)
-
diff --git a/tests/92_pkpy.py b/tests/92_pkpy.py
new file mode 100644
index 00000000..8c0b164d
--- /dev/null
+++ b/tests/92_pkpy.py
@@ -0,0 +1,8 @@
+from pkpy import is_user_defined_type
+
+class A:
+    pass
+
+assert is_user_defined_type(A)
+assert not is_user_defined_type(int)
+assert not is_user_defined_type(dict)
\ No newline at end of file