googleapis
diff --git a/google/api_core/retry.py b/google/api_core/retry.py
@@ -203,8 +203,8 @@ def retry_target(target, predicate, sleep_generator, deadline, on_error=None):
         if deadline_datetime is not None:
             if deadline_datetime <= now:
                 raise exceptions.RetryError(
-                    "Deadline of {:.1f}s exceeded while calling {}".format(
-                        deadline, target
+                    "Deadline of {:.1f}s exceeded while calling target function".format(
+                        deadline
                     ),
                     last_exc,
                 ) from last_exc

diff --git a/google/api_core/retry_async.py b/google/api_core/retry_async.py
@@ -132,8 +132,8 @@ async def retry_target(target, predicate, sleep_generator, deadline, on_error=No
                 # Chains the raising RetryError with the root cause error,
                 # which helps observability and debugability.
                 raise exceptions.RetryError(
-                    "Deadline of {:.1f}s exceeded while calling {}".format(
-                        deadline, target
+                    "Deadline of {:.1f}s exceeded while calling target function".format(
+                        deadline
                     ),
                     last_exc,
                 ) from last_exc

diff --git a/tests/asyncio/test_retry_async.py b/tests/asyncio/test_retry_async.py
@@ -120,6 +120,10 @@ async def test_retry_target_deadline_exceeded(utcnow, sleep):
     assert exc_info.match("last exception: meep")
     assert target.call_count == 2
 
+    # Ensure the exception message does not include the target fn:
+    # it may be a partial with user data embedded
+    assert str(target) not in exc_info.exconly()
+
 
 @pytest.mark.asyncio
 async def test_retry_target_bad_sleep_generator():

diff --git a/tests/unit/test_retry.py b/tests/unit/test_retry.py
@@ -152,6 +152,10 @@ def test_retry_target_deadline_exceeded(utcnow, sleep):
     assert exc_info.match("last exception: meep")
     assert target.call_count == 2
 
+    # Ensure the exception message does not include the target fn:
+    # it may be a partial with user data embedded
+    assert str(target) not in exc_info.exconly()
+
 
 def test_retry_target_bad_sleep_generator():
     with pytest.raises(ValueError, match="Sleep generator"):