diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index 50fd4634ae..a572fc87b9 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -10,7 +10,7 @@ Added
 * Continue introducing `pants <https://www.pantsbuild.org/docs>`_ to improve DX (Developer Experience)
   working on StackStorm, improve our security posture, and improve CI reliability thanks in part
   to pants' use of PEX lockfiles. This is not a user-facing addition.
-  #5778 #5789 #5817 #5795 #5830
+  #5778 #5789 #5817 #5795 #5830 #5833
   Contributed by @cognifloyd
 
 
diff --git a/contrib/core/tests/BUILD b/contrib/core/tests/BUILD
index dabf212d7e..b679ff82cf 100644
--- a/contrib/core/tests/BUILD
+++ b/contrib/core/tests/BUILD
@@ -1 +1,12 @@
-python_tests()
+python_tests(
+    overrides={
+        "test_action_sendmail.py": {
+            "dependencies": [
+                # contrib/core is symlinked to st2tests/st2tests/fixtures/packs/core
+                # so pants thinks "mail-parser" is defined twice, making it ambiguous.
+                # Use contrib/core as the canonical copy.
+                "contrib/core:reqs#mail-parser",
+            ],
+        }
+    },
+)
diff --git a/contrib/packs/tests/BUILD b/contrib/packs/tests/BUILD
index dabf212d7e..3a89bff937 100644
--- a/contrib/packs/tests/BUILD
+++ b/contrib/packs/tests/BUILD
@@ -1 +1,10 @@
-python_tests()
+python_tests(
+    overrides={
+        "test_action_download.py": {
+            "dependencies": [
+                # imports tests.fixtures which is ambiguous. Tell pants which one to use.
+                "contrib/packs/tests/fixtures",
+            ],
+        }
+    },
+)
diff --git a/contrib/runners/orquesta_runner/tests/unit/BUILD b/contrib/runners/orquesta_runner/tests/unit/BUILD
index 00e59b3017..5934dd9b24 100644
--- a/contrib/runners/orquesta_runner/tests/unit/BUILD
+++ b/contrib/runners/orquesta_runner/tests/unit/BUILD
@@ -1,5 +1,9 @@
 python_tests(
     name="tests",
+    dependencies=[
+        # most files import tests.unit.base which is ambiguous. Tell pants which one to use.
+        "contrib/runners/orquesta_runner/tests/unit/base.py",
+    ],
 )
 
 python_sources()
diff --git a/st2auth/tests/unit/BUILD b/st2auth/tests/unit/BUILD
index 57341b1358..bd52dfb436 100644
--- a/st2auth/tests/unit/BUILD
+++ b/st2auth/tests/unit/BUILD
@@ -1,3 +1,7 @@
 python_tests(
     name="tests",
+    dependencies=[
+        # most files import tests.base which is ambiguous. Tell pants which one to use.
+        "st2auth/tests/base.py",
+    ],
 )
diff --git a/st2auth/tests/unit/controllers/v1/BUILD b/st2auth/tests/unit/controllers/v1/BUILD
index 57341b1358..bd52dfb436 100644
--- a/st2auth/tests/unit/controllers/v1/BUILD
+++ b/st2auth/tests/unit/controllers/v1/BUILD
@@ -1,3 +1,7 @@
 python_tests(
     name="tests",
+    dependencies=[
+        # most files import tests.base which is ambiguous. Tell pants which one to use.
+        "st2auth/tests/base.py",
+    ],
 )
diff --git a/st2client/tests/unit/BUILD b/st2client/tests/unit/BUILD
index 57341b1358..9aaca5d249 100644
--- a/st2client/tests/unit/BUILD
+++ b/st2client/tests/unit/BUILD
@@ -1,3 +1,7 @@
 python_tests(
     name="tests",
+    dependencies=[
+        # most files import tests.base which is ambiguous. Tell pants which one to use.
+        "st2client/tests/base.py",
+    ],
 )
diff --git a/st2common/tests/unit/BUILD b/st2common/tests/unit/BUILD
index 00e59b3017..34cacadb2b 100644
--- a/st2common/tests/unit/BUILD
+++ b/st2common/tests/unit/BUILD
@@ -1,5 +1,9 @@
 python_tests(
     name="tests",
+    dependencies=[
+        # several files import tests.unit.base which is ambiguous. Tell pants which one to use.
+        "st2common/tests/unit/base.py",
+    ],
 )
 
 python_sources()