diff --git a/CHANGES.current b/CHANGES.current
index 64e4c4402..56cb2c560 100644
--- a/CHANGES.current
+++ b/CHANGES.current
@@ -7,6 +7,14 @@ the issue number to the end of the URL: https://github.com/swig/swig/issues/
 Version 4.1.0 (in progress)
 ===========================
 
+2022-03-26: eltoder
+            [Python] #1684 Use different capsule names with and without -builtin
+
+            Types generated with and without -builtin are not compatible. Mixing
+            them in a common type list leads to crashes. Avoid this by using
+            different capsule names: "type_pointer_capsule" without -builtin and
+            "type_pointer_capsule_builtin" with.
+
 2022-03-15: ianlancetaylor
 	    [Go] Don't convert arrays to pointers if there is a "gotype"
 	    typemap entry.
diff --git a/Examples/test-suite/python/python_runtime_data_runme.py b/Examples/test-suite/python/python_runtime_data_runme.py
index 341315ee3..063bf82d1 100644
--- a/Examples/test-suite/python/python_runtime_data_runme.py
+++ b/Examples/test-suite/python/python_runtime_data_runme.py
@@ -1,11 +1,15 @@
 import python_runtime_data_builtin as builtin
 import python_runtime_data_nobuiltin as nobuiltin
 
-assert builtin.is_python_builtin()
-assert not nobuiltin.is_python_builtin()
+def swig_assert(a):
+    if not a:
+        raise RuntimeError("Failed")
+
+swig_assert(builtin.is_python_builtin())
+swig_assert(not nobuiltin.is_python_builtin())
 
 for i in range(1, 5):
     v1 = builtin.vectord([1.] * i)
-    assert len(v1) == i
+    swig_assert(len(v1) == i)
     v2 = nobuiltin.vectord([1.] * i)
-    assert len(v2) == i
+    swig_assert(len(v2) == i)