diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index a47c36ad..ebfad8fd 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -108,8 +108,10 @@ jobs:
             python_version: '3.14'
           - tox_env: py314-m_ans-ans12
             python_version: '3.14'
+          - tox_env: py314-m_ans-ans13
+            python_version: '3.14'
 
-          - tox_env: py314-m_ans-ans12-s_lin
+          - tox_env: py314-m_ans-ans13-s_lin
             python_version: '3.14'
 
           - tox_env: py314-m_mtg
@@ -159,9 +161,9 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - tox_env: py314-m_lcl-ans12
+          - tox_env: py314-m_lcl-ans13
             python_version: '3.14'
-          - tox_env: py314-m_lcl-ans12-s_lin
+          - tox_env: py314-m_lcl-ans13-s_lin
             python_version: '3.14'
 
           - tox_env: py314-m_mtg
diff --git a/docs/changelog.rst b/docs/changelog.rst
index 0d838c5c..67d4dfb5 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -21,6 +21,9 @@ To avail of fixes in an unreleased version, please download a ZIP file
 In progress (unreleased)
 ------------------------
 
+* :gh:issue:`1354` :mod:`ansible_mitogen`: ansible_mitogen: Ansible 13
+  (ansible-core 2.20) support
+
 
 v0.3.32 (2025-11-21)
 --------------------
diff --git a/tox.ini b/tox.ini
index aac84fa8..fba4ccf3 100644
--- a/tox.ini
+++ b/tox.ini
@@ -13,10 +13,10 @@
 # 3.5  <= 2.11    <= 2.15    <= 5.5     <= 2.2.28  <= 2.11.3  <= 20      <= 5.9.5   <= 6.1.0   <= 3.28    <= 20.15²
 # 3.6  <= 2.11    <= 2.16    <= 6.2     <= 3.2.20  <= 3.0.3   <= 21                 <= 7.0.1   <= 3.28    <= 20.17²
 # 3.7  <= 2.12    <= 2.17    <= 7.2.7   <= 3.2.20                                   <= 7.4.4   <= 4.8.0   <= 20.26.6²
-# 3.8  <= 2.12
+# 3.8  <= 2.12    <= 2.19
 # 3.9  <= 2.15
 # 3.10 <= 2.17
-# 3.11
+# 3.11 <= 2.19
 # 3.12            >= 2.13¹
 #
 # Notes
@@ -50,6 +50,7 @@
 # ansible == 10.x    ansible-core ~= 2.17.0
 # ansible == 11.x    ansible-core ~= 2.18.0
 # ansible == 12.x    ansible-core ~= 2.19.0
+# ansible == 13.x    ansible-core ~= 2.20.0
 
 # See also
 # - https://docs.ansible.com/ansible/devel/reference_appendices/release_and_maintenance.html#ansible-core-support-matrix
@@ -93,6 +94,7 @@ deps =
     ans10: ansible~=10.0
     ans11: ansible~=11.0
     ans12: ansible~=12.0
+    ans13: ansible~=13.0
 install_command =
     python -m pip --no-python-version-warning --disable-pip-version-check install {opts} {packages}
 commands_pre =
@@ -127,6 +129,8 @@ setenv =
     # Ansible 11 (ansible-core 2.18) requires Python >= 3.8 on targets
     ans11: MITOGEN_TEST_DISTRO_SPECS=debian11-py3 ubuntu2004-py3
     ans12: MITOGEN_TEST_DISTRO_SPECS=debian11-py3 ubuntu2004-py3
+    # Ansible 13 (ansible-core 2.20) requires Python >= 3.9 on targets
+    ans13: MITOGEN_TEST_DISTRO_SPECS=debian11-py3
     distros_centos: MITOGEN_TEST_DISTRO_SPECS=centos6 centos7 centos8
     distros_centos5: MITOGEN_TEST_DISTRO_SPECS=centos5
     distros_centos6: MITOGEN_TEST_DISTRO_SPECS=centos6