diff --git a/Lib/test/test_capi/test_exceptions.py b/Lib/test/test_capi/test_exceptions.py
index 1bff65b6559f0b..5903b782d9ca8c 100644
--- a/Lib/test/test_capi/test_exceptions.py
+++ b/Lib/test/test_capi/test_exceptions.py
@@ -3,11 +3,12 @@
 import re
 import sys
 import unittest
+import textwrap
 
 from test import support
 from test.support import import_helper
-from test.support.os_helper import TESTFN, TESTFN_UNDECODABLE
-from test.support.script_helper import assert_python_failure
+from test.support.os_helper import TESTFN, TESTFN_UNDECODABLE, unlink
+from test.support.script_helper import assert_python_failure, assert_python_ok
 from test.support.testcase import ExceptionIsLikeMixin
 
 from .test_misc import decode_stderr
@@ -68,6 +69,52 @@ def test_exc_info(self):
         else:
             self.assertTrue(False)
 
+    def test_warn_with_stacklevel(self):
+        self.addCleanup(unlink, TESTFN)
+        with open(TESTFN, 'w', encoding='utf-8') as f:
+            f.write(textwrap.dedent('''\
+            import _testcapi
+
+            def foo():
+                _testcapi.function_set_warning()
+
+            foo()  # line 6
+
+
+            foo()  # line 9
+            '''))
+        proc = assert_python_ok(TESTFN)
+        warnings = proc.err.splitlines()
+        expected = [
+            b':6: RuntimeWarning: Testing PyErr_WarnEx',
+            b'  foo()  # line 6',
+            b':9: RuntimeWarning: Testing PyErr_WarnEx',
+            b'  foo()  # line 9',
+        ]
+        self.assertEqual(len(warnings), len(expected))
+        for index, entry in enumerate(warnings):
+            self.assertIn(expected[index], entry)
+
+    def test_warn_during_finalization(self):
+        self.addCleanup(unlink, TESTFN)
+        with open(TESTFN, 'w', encoding='utf8') as f:
+            f.write(textwrap.dedent('''\
+            import _testcapi
+
+            class Foo:
+                def foo(self):
+                    _testcapi.function_set_warning()
+                def __del__(self):
+                    self.foo()
+
+            ref = Foo()
+            '''))
+        proc = assert_python_ok(TESTFN)
+        warnings = proc.err.splitlines()
+        # Due to the finalization of the interpreter, the source will be ommited
+        # because the ``warnings`` module cannot be imported at this time
+        self.assertEqual(len(warnings), 1)
+        self.assertIn(b':7: RuntimeWarning: Testing PyErr_WarnEx', warnings[0])
 
 class Test_FatalError(unittest.TestCase):
 
diff --git a/Misc/NEWS.d/next/Core and Builtins/2024-05-16-23-02-03.gh-issue-119049.qpd_S-.rst b/Misc/NEWS.d/next/Core and Builtins/2024-05-16-23-02-03.gh-issue-119049.qpd_S-.rst
new file mode 100644
index 00000000000000..1d7aad8d1e5be6
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2024-05-16-23-02-03.gh-issue-119049.qpd_S-.rst	
@@ -0,0 +1,2 @@
+Fix displaying the source line for warnings created by the C API if the
+:mod:`warnings` module had not yet been imported.
diff --git a/Modules/_testcapimodule.c b/Modules/_testcapimodule.c
index edd137f30ca9ba..7068fe5ff48cd2 100644
--- a/Modules/_testcapimodule.c
+++ b/Modules/_testcapimodule.c
@@ -3230,6 +3230,15 @@ test_atexit(PyObject *self, PyObject *Py_UNUSED(args))
 
 static PyObject *test_buildvalue_issue38913(PyObject *, PyObject *);
 
+static PyObject *
+function_set_warning(PyObject *Py_UNUSED(module), PyObject *Py_UNUSED(args))
+{
+    if (PyErr_WarnEx(PyExc_RuntimeWarning, "Testing PyErr_WarnEx", 2)) {
+        return NULL;
+    }
+    Py_RETURN_NONE;
+}
+
 static PyMethodDef TestMethods[] = {
     {"set_errno",               set_errno,                       METH_VARARGS},
     {"test_config",             test_config,                     METH_NOARGS},
@@ -3369,6 +3378,7 @@ static PyMethodDef TestMethods[] = {
     {"function_get_kw_defaults", function_get_kw_defaults, METH_O, NULL},
     {"function_set_kw_defaults", function_set_kw_defaults, METH_VARARGS, NULL},
     {"test_atexit", test_atexit, METH_NOARGS},
+    {"function_set_warning", function_set_warning, METH_NOARGS},
     {NULL, NULL} /* sentinel */
 };
 
diff --git a/Python/_warnings.c b/Python/_warnings.c
index 1f91edbf5cb5dc..e04607d44442a9 100644
--- a/Python/_warnings.c
+++ b/Python/_warnings.c
@@ -571,10 +571,9 @@ call_show_warning(PyThreadState *tstate, PyObject *category,
     PyObject *show_fn, *msg, *res, *warnmsg_cls = NULL;
     PyInterpreterState *interp = tstate->interp;
 
-    /* If the source parameter is set, try to get the Python implementation.
-       The Python implementation is able to log the traceback where the source
+    /* The Python implementation is able to log the traceback where the source
        was allocated, whereas the C implementation doesn't. */
-    show_fn = GET_WARNINGS_ATTR(interp, _showwarnmsg, source != NULL);
+    show_fn = GET_WARNINGS_ATTR(interp, _showwarnmsg, 1);
     if (show_fn == NULL) {
         if (PyErr_Occurred())
             return -1;