diff --git a/ansible_mitogen/loaders.py b/ansible_mitogen/loaders.py
index 123dd4ac..9597e3ee 100644
--- a/ansible_mitogen/loaders.py
+++ b/ansible_mitogen/loaders.py
@@ -49,7 +49,7 @@ __all__ = [
 
 
 ANSIBLE_VERSION_MIN = (2, 10)
-ANSIBLE_VERSION_MAX = (2, 18)
+ANSIBLE_VERSION_MAX = (2, 19)
 
 NEW_VERSION_MSG = (
     "Your Ansible version (%s) is too recent. The most recent version\n"
diff --git a/ansible_mitogen/utils/unsafe.py b/ansible_mitogen/utils/unsafe.py
index b2c3d533..c1bdaee7 100644
--- a/ansible_mitogen/utils/unsafe.py
+++ b/ansible_mitogen/utils/unsafe.py
@@ -31,7 +31,12 @@ _CAST_DISPATCH = {
 }
 _CAST_DISPATCH.update({t: _passthrough for t in mitogen.utils.PASSTHROUGH})
 
-if hasattr(ansible.utils.unsafe_proxy.AnsibleUnsafeText, '_strip_unsafe'):
+if ansible_mitogen.utils.ansible_version[:2] >= (2, 19):
+    _CAST_DISPATCH.update({
+        ansible.utils.unsafe_proxy.AnsibleUnsafeBytes: bytes,
+        ansible.utils.unsafe_proxy.AnsibleUnsafeText: mitogen.core.UnicodeType,
+    })
+elif hasattr(ansible.utils.unsafe_proxy.AnsibleUnsafeText, '_strip_unsafe'):
     _CAST_DISPATCH.update({
         ansible.utils.unsafe_proxy.AnsibleUnsafeBytes: _cast_unsafe,
         ansible.utils.unsafe_proxy.AnsibleUnsafeText: _cast_unsafe,
diff --git a/docs/changelog.rst b/docs/changelog.rst
index 69755988..9f059eed 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -21,6 +21,7 @@ To avail of fixes in an unreleased version, please download a ZIP file
 In progress (unreleased)
 ------------------------
 
+* :gh:issue:`1258` Initial Ansible 12 (ansible-core 2.19) support
 
 
 v0.3.24 (2025-05-29)
diff --git a/tox.ini b/tox.ini
index ddb8c88d..67d6cf45 100644
--- a/tox.ini
+++ b/tox.ini
@@ -47,6 +47,7 @@
 # ansible == 9.x     ansible-core ~= 2.16.0
 # ansible == 10.x    ansible-core ~= 2.17.0
 # ansible == 11.x    ansible-core ~= 2.18.0
+# ansible == 12.x    ansible-core ~= 2.19.0
 
 # See also
 # - https://docs.ansible.com/ansible/latest/reference_appendices/release_and_maintenance.html#ansible-core-support-matrix
@@ -56,7 +57,7 @@ envlist =
     init,
     py{27,36}-mode_ansible-ansible{2.10,3,4},
     py{311}-mode_ansible-ansible{2.10,3,4,5},
-    py{313}-mode_ansible-ansible{6,7,8,9,10,11},
+    py{313}-mode_ansible-ansible{6,7,8,9,10,11,12},
     py{27,36,313}-mode_mitogen,
     report,
 
@@ -85,7 +86,8 @@ deps =
     ansible8: ansible~=8.0
     ansible9: ansible~=9.0
     ansible10: ansible~=10.0
-    ansible11: ansible>=11.0
+    ansible11: ansible~=11.0
+    ansible12: ansible>=12.0a
 install_command =
     python -m pip --no-python-version-warning --disable-pip-version-check install {opts} {packages}
 commands_pre =
@@ -118,6 +120,7 @@ setenv =
     ansible10: MITOGEN_TEST_DISTRO_SPECS=debian10-py3 debian11-py3 ubuntu2004-py3
     # Ansible 11 (ansible-core 2.18) requires Python >= 3.8 on targets
     ansible11: MITOGEN_TEST_DISTRO_SPECS=debian11-py3 ubuntu2004-py3
+    ansible12: MITOGEN_TEST_DISTRO_SPECS=debian11-py3 ubuntu2004-py3
     distros_centos: MITOGEN_TEST_DISTRO_SPECS=centos6 centos7 centos8
     distros_centos5: MITOGEN_TEST_DISTRO_SPECS=centos5
     distros_centos6: MITOGEN_TEST_DISTRO_SPECS=centos6