diff --git a/grudge/execution.py b/grudge/execution.py
index 54f93a63602f8c34f47f238d4c3a14d2f2063767..102fa108a94e7c3ec0f0999ce46ac02f10da4b10 100644
--- a/grudge/execution.py
+++ b/grudge/execution.py
@@ -44,9 +44,6 @@ logger = logging.getLogger(__name__)
 from loopy.version import LOOPY_USE_LANGUAGE_VERSION_2018_2  # noqa: F401
 
 
-MPI_TAG_SEND_TAGS = 1729
-
-
 ResultType = Union[DOFArray, Number]
 
 
diff --git a/grudge/symbolic/compiler.py b/grudge/symbolic/compiler.py
index 075c0b07f30375f3a010651d305005fd920c61e2..85eb4514254575bcd6c2543472b87168f9d38124 100644
--- a/grudge/symbolic/compiler.py
+++ b/grudge/symbolic/compiler.py
@@ -212,8 +212,7 @@ class RankDataSwapAssign(Instruction):
     .. attribute:: dd_out
     .. attribute:: comment
     """
-    # TODO: We need to be sure this does not conflict with some other tag.
-    MPI_TAG_GRUDGE_DATA_BASE = 0x3700d3e
+    MPI_TAG_GRUDGE_DATA_BASE = 15165
 
     def __init__(self, name, field, op):
         self.name = name