diff --git a/graalpython/com.oracle.graal.python.test/src/tests/test_itertools_count.py b/graalpython/com.oracle.graal.python.test/src/tests/test_itertools_count.py
new file mode 100644
index 0000000000..f2761133d4
--- /dev/null
+++ b/graalpython/com.oracle.graal.python.test/src/tests/test_itertools_count.py
@@ -0,0 +1,67 @@
+# Copyright (c) 2026, Oracle and/or its affiliates. All rights reserved.
+# DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+#
+# The Universal Permissive License (UPL), Version 1.0
+#
+# Subject to the condition set forth below, permission is hereby granted to any
+# person obtaining a copy of this software, associated documentation and/or
+# data (collectively the "Software"), free of charge and under any and all
+# copyright rights in the Software, and any and all patent rights owned or
+# freely licensable by each licensor hereunder covering either (i) the
+# unmodified Software as contributed to or provided by such licensor, or (ii)
+# the Larger Works (as defined below), to deal in both
+#
+# (a) the Software, and
+#
+# (b) any piece of software and/or hardware listed in the lrgrwrks.txt file if
+# one is included with the Software each a "Larger Work" to which the Software
+# is contributed by such licensors),
+#
+# without restriction, including without limitation the rights to copy, create
+# derivative works of, display, perform, and distribute the Software and make,
+# use, sell, offer for sale, import, export, have made, and have sold the
+# Software and the Larger Work(s), and to sublicense the foregoing rights on
+# either these or other terms.
+#
+# This license is subject to the following condition:
+#
+# The above copyright notice and either this complete permission notice or at a
+# minimum a reference to the UPL must be included in all copies or substantial
+# portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+import itertools
+
+
+def assert_raises(err, fn, *args, **kwargs):
+    raised = False
+    try:
+        fn(*args, **kwargs)
+    except err:
+        raised = True
+    assert raised
+
+
+def test_count_rejects_none_start():
+    assert_raises(TypeError, itertools.count, None)
+    assert_raises(TypeError, itertools.count, start=None)
+
+
+def test_count_rejects_none_step():
+    assert_raises(TypeError, itertools.count, 0, None)
+    assert_raises(TypeError, itertools.count, step=None)
+
+
+def test_count_defaults():
+    c = itertools.count()
+    assert next(c) == 0
+    assert next(c) == 1
+    c = itertools.count(5)
+    assert next(c) == 5
+    assert next(c) == 6
diff --git a/graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/itertools/CountBuiltins.java b/graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/itertools/CountBuiltins.java
index b3cd281f78..33efaff3f1 100644
--- a/graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/itertools/CountBuiltins.java
+++ b/graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/itertools/CountBuiltins.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2021, 2026, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * The Universal Permissive License (UPL), Version 1.0
@@ -100,8 +100,8 @@ protected List<? extends NodeFactory<? extends PythonBuiltinBaseNode>> getNodeFa
 
     @Slot(value = SlotKind.tp_new, isComplex = true)
     @SlotSignature(name = "count", minNumOfPositionalArgs = 1, parameterNames = {"cls", "start", "step"})
-    @ArgumentClinic(name = "start", defaultValue = "0", useDefaultForNone = true)
-    @ArgumentClinic(name = "step", defaultValue = "1", useDefaultForNone = true)
+    @ArgumentClinic(name = "start", defaultValue = "0")
+    @ArgumentClinic(name = "step", defaultValue = "1")
     @GenerateNodeFactory
     public abstract static class CountNode extends PythonTernaryClinicBuiltinNode {