diff --git a/.ci/ansible_install.py b/.ci/ansible_install.py
index 900303f6..3b217ff2 100755
--- a/.ci/ansible_install.py
+++ b/.ci/ansible_install.py
@@ -4,7 +4,7 @@ import ci_lib
 
 batches = [
     [
-        'aws ecr-public get-login-password | docker login --username AWS --password-stdin public.ecr.aws',
+        'if [ "${TF_BUILD:-false}" = "True" ]; then aws ecr-public get-login-password | docker login --username AWS --password-stdin public.ecr.aws; fi',
     ]
 ]
 
diff --git a/.ci/debops_common_install.py b/.ci/debops_common_install.py
index afafe39a..565f9488 100755
--- a/.ci/debops_common_install.py
+++ b/.ci/debops_common_install.py
@@ -10,7 +10,7 @@ ci_lib.run_batches([
         'python -m pip --no-python-version-warning --disable-pip-version-check "debops[ansible]==2.1.2"',
     ],
     [
-        'aws ecr-public get-login-password | docker login --username AWS --password-stdin public.ecr.aws',
+        'if [ "${TF_BUILD:-false}" = "True" ]; then aws ecr-public get-login-password | docker login --username AWS --password-stdin public.ecr.aws; fi',
     ],
 ])
 
diff --git a/.ci/mitogen_install.py b/.ci/mitogen_install.py
index b0b1eb14..23ff384b 100755
--- a/.ci/mitogen_install.py
+++ b/.ci/mitogen_install.py
@@ -7,7 +7,7 @@ batches = [
 
 if ci_lib.have_docker():
     batches.append([
-        'aws ecr-public get-login-password | docker login --username AWS --password-stdin public.ecr.aws',
+        'if [ "${TF_BUILD:-false}" = "True" ]; then aws ecr-public get-login-password | docker login --username AWS --password-stdin public.ecr.aws; fi',
     ])
 
 
diff --git a/.ci/mitogen_py24_install.py b/.ci/mitogen_py24_install.py
index bd6ecb24..8af90405 100755
--- a/.ci/mitogen_py24_install.py
+++ b/.ci/mitogen_py24_install.py
@@ -4,7 +4,7 @@ import ci_lib
 
 batches = [
     [
-        'aws ecr-public get-login-password | docker login --username AWS --password-stdin public.ecr.aws',
+        'if [ "${TF_BUILD:-false}" = "True" ]; then aws ecr-public get-login-password | docker login --username AWS --password-stdin public.ecr.aws; fi',
     ],
     [
         'curl https://dw.github.io/mitogen/binaries/ubuntu-python-2.4.6.tar.bz2 | sudo tar -C / -jxv',
diff --git a/tox.ini b/tox.ini
index a0b0e1ae..5dcb1bf2 100644
--- a/tox.ini
+++ b/tox.ini
@@ -104,6 +104,9 @@ passenv =
     AWS_DEFAULT_REGION
     AWS_SECRET_ACCESS_KEY
     HOME
+    # Azure DevOps, TF_BUILD is set to 'True' when running in a build task
+    # https://learn.microsoft.com/en-us/azure/devops/pipelines/build/variables
+    TF_BUILD
 setenv =
     # See also azure-pipelines.yml
     ANSIBLE_STRATEGY = mitogen_linear