diff --git a/src/spacepackets/ecss/pus_17_test.py b/src/spacepackets/ecss/pus_17_test.py
index 3761922..11d57ee 100644
--- a/src/spacepackets/ecss/pus_17_test.py
+++ b/src/spacepackets/ecss/pus_17_test.py
@@ -16,6 +16,9 @@ class MessageSubtype(enum.IntEnum):
     TM_REPLY = 2
 
 
+Subservice = MessageSubtype
+
+
 class Service17Tm(AbstractPusTm):
     def __init__(
         self,
diff --git a/src/spacepackets/ecss/pus_3_hk.py b/src/spacepackets/ecss/pus_3_hk.py
index 5225c88..7ddce59 100644
--- a/src/spacepackets/ecss/pus_3_hk.py
+++ b/src/spacepackets/ecss/pus_3_hk.py
@@ -21,3 +21,6 @@ class MessageSubtype(enum.IntEnum):
 
     TC_MODIFY_PARAMETER_REPORT_COLLECTION_INTERVAL = 31
     TC_MODIFY_DIAGNOSTICS_REPORT_COLLECTION_INTERVAL = 32
+
+
+Subservice = MessageSubtype
diff --git a/src/spacepackets/ecss/pus_5_event.py b/src/spacepackets/ecss/pus_5_event.py
index 49732e8..ee9aa0e 100644
--- a/src/spacepackets/ecss/pus_5_event.py
+++ b/src/spacepackets/ecss/pus_5_event.py
@@ -8,3 +8,6 @@ class MessageSubtype(enum.IntEnum):
     TM_HIGH_SEVERITY_EVENT = 4
     TC_ENABLE_EVENT_REPORTING = 5
     TC_DISABLE_EVENT_REPORTING = 6
+
+
+Subservice = MessageSubtype
diff --git a/tests/ecss/test_message_subtype_compat.py b/tests/ecss/test_message_subtype_compat.py
new file mode 100644
index 0000000..9aff3fb
--- /dev/null
+++ b/tests/ecss/test_message_subtype_compat.py
@@ -0,0 +1,14 @@
+from unittest import TestCase
+
+from spacepackets.ecss import pus_3_hk, pus_5_event, pus_17_test
+
+
+class TestMessageSubtypeCompat(TestCase):
+    def test_service_17_exports_legacy_subservice_enum_alias(self):
+        self.assertIs(pus_17_test.Subservice, pus_17_test.MessageSubtype)
+
+    def test_service_3_exports_legacy_subservice_enum_alias(self):
+        self.assertIs(pus_3_hk.Subservice, pus_3_hk.MessageSubtype)
+
+    def test_service_5_exports_legacy_subservice_enum_alias(self):
+        self.assertIs(pus_5_event.Subservice, pus_5_event.MessageSubtype)