diff --git a/roles/generate-zuul-manifest/library/generate_manifest.py b/roles/generate-zuul-manifest/library/generate_manifest.py
index 5e1240a2a..40f5eb35c 100644
--- a/roles/generate-zuul-manifest/library/generate_manifest.py
+++ b/roles/generate-zuul-manifest/library/generate_manifest.py
@@ -23,7 +23,9 @@ import sys
 from ansible.module_utils.basic import AnsibleModule
 
 
-mimetypes.init()
+if not mimetypes.inited:
+    # We don't want to reinit and override any previously added types.
+    mimetypes.init()
 
 
 def path_in_tree(root, path):
diff --git a/roles/test-upload-logs-swift/library/zuul_swift_upload.py b/roles/test-upload-logs-swift/library/zuul_swift_upload.py
index fc2220a56..b2df12c39 100755
--- a/roles/test-upload-logs-swift/library/zuul_swift_upload.py
+++ b/roles/test-upload-logs-swift/library/zuul_swift_upload.py
@@ -60,7 +60,9 @@ try:
 except ImportError:
     from collections import Sequence
 
-mimetypes.init()
+if not mimetypes.inited:
+    # We don't want to reinit and override any previously inited types.
+    mimetypes.init()
 mimetypes.add_type('text/plain', '.yaml')
 
 MAX_UPLOAD_THREADS = 24
diff --git a/roles/upload-logs-base/module_utils/zuul_jobs/upload_utils.py b/roles/upload-logs-base/module_utils/zuul_jobs/upload_utils.py
index 9b6353f83..51e551785 100644
--- a/roles/upload-logs-base/module_utils/zuul_jobs/upload_utils.py
+++ b/roles/upload-logs-base/module_utils/zuul_jobs/upload_utils.py
@@ -47,7 +47,9 @@ try:
 except ImportError:
     from collections import Sequence
 
-mimetypes.init()
+if not mimetypes.inited:
+    # We don't want to reinit and override any previously added types.
+    mimetypes.init()
 mimetypes.add_type('text/plain', '.yaml')
 
 MAX_UPLOAD_THREADS = 24