diff --git a/insteon_mqtt/device/base/Base.py b/insteon_mqtt/device/base/Base.py
index aa11013c..b3b49909 100644
--- a/insteon_mqtt/device/base/Base.py
+++ b/insteon_mqtt/device/base/Base.py
@@ -588,6 +588,10 @@ def addRefreshData(self, seq, force=False):
         if self.db.desc is None or self.db.firmware is None or force:
             seq.add(self.get_model)
 
+        # If the engine is not known, or force true, run get_engine
+        if self.db.engine is None or force:
+            seq.add(self.get_engine)
+
     #-----------------------------------------------------------------------
     def get_flags(self, on_done=None):
         """Get the Insteon operational flags field from the device.
@@ -649,6 +653,23 @@ def get_model(self, on_done=None):
                                                    on_done)
         self.send(msg, msg_handler)
 
+    def _set_operating_flag_msg(self, cmd2):
+        """Creates a set operating flags message
+
+        This will create the appropriate message based on the device's
+        engine (extended for i2cs, else standard)
+
+        Args:
+          cmd2 (int): the set operating flags option (i.e. 0x04 to enable
+                      resume dim)
+        """
+        cmd1 = Msg.CmdType.SET_OPERATING_FLAGS
+        if self.db.engine is not None and self.db.engine < 2:
+            return Msg.OutStandard.direct(self.addr, cmd1, cmd2)
+        else:
+            return Msg.OutExtended.direct(self.addr, cmd1, cmd2,
+                                          bytes([0x00] * 14), crc_type='D14')
+
     #-----------------------------------------------------------------------
     def sync(self, dry_run=True, refresh=True, sequence=None, on_done=None):
         """Syncs the links on the device.
diff --git a/insteon_mqtt/device/base/DimmerBase.py b/insteon_mqtt/device/base/DimmerBase.py
index bd31c137..d256ef9f 100644
--- a/insteon_mqtt/device/base/DimmerBase.py
+++ b/insteon_mqtt/device/base/DimmerBase.py
@@ -167,14 +167,10 @@ def set_resume_dim(self, on_done=None, **kwargs):
         # 0x05 - Disables resume dim
         if resume_dim:
             LOG.info("Device %s enabling resume dim", self.label)
-            cmd2 = 0x04
+            msg = self._set_operating_flag_msg(0x04)
         else:
             LOG.info("Device %s disabling resume dim", self.label)
-            cmd2 = 0x05
-
-        cmd1 = Msg.CmdType.SET_OPERATING_FLAGS
-        msg = Msg.OutExtended.direct(self.addr, cmd1, cmd2,
-                                      bytes([0x00] * 14))
+            msg = self._set_operating_flag_msg(0x05)
 
         # Use the standard command handler which will notify us when the
         # command is ACK'ed.
diff --git a/tests/device/test_DimmerDev.py b/tests/device/test_DimmerDev.py
index c420c11c..cc732a1f 100644
--- a/tests/device/test_DimmerDev.py
+++ b/tests/device/test_DimmerDev.py
@@ -73,11 +73,34 @@ def test_handle_on_off_manual(self, test_device, group, cmd1, cmd2, expected):
             else:
                 mocked.assert_not_called()
 
-    def test_set_resume_dim(self, test_device):
+    def test_set_resume_dim_non_i2cs(self, test_device):
         # set_resume_dim(self, resume_dim, on_done=None)
         for params in ([True, 0x04], [False, 0x05]):
             test_device.set_resume_dim(resume_dim=params[0])
             assert len(test_device.protocol.sent) == 1
+            assert isinstance(test_device.protocol.sent[0].msg, Msg.OutStandard)
+            assert test_device.protocol.sent[0].msg.cmd1 == 0x20
+            assert test_device.protocol.sent[0].msg.cmd2 == params[1]
+            test_device.protocol.clear()
+
+    def test_set_resume_dim_unknown(self, test_device):
+        # set_resume_dim(self, resume_dim, on_done=None)
+        test_device.db.engine = None
+        for params in ([True, 0x04], [False, 0x05]):
+            test_device.set_resume_dim(resume_dim=params[0])
+            assert len(test_device.protocol.sent) == 1
+            assert isinstance(test_device.protocol.sent[0].msg, Msg.OutStandard)
+            assert test_device.protocol.sent[0].msg.cmd1 == 0x20
+            assert test_device.protocol.sent[0].msg.cmd2 == params[1]
+            test_device.protocol.clear()
+            
+    def test_set_resume_dim_i2cs(self, test_device):
+        # set_resume_dim(self, resume_dim, on_done=None)
+        test_device.db.engine = 2
+        for params in ([True, 0x04], [False, 0x05]):
+            test_device.set_resume_dim(resume_dim=params[0])
+            assert len(test_device.protocol.sent) == 1
+            assert isinstance(test_device.protocol.sent[0].msg, Msg.OutExtended)
             assert test_device.protocol.sent[0].msg.cmd1 == 0x20
             assert test_device.protocol.sent[0].msg.cmd2 == params[1]
             assert test_device.protocol.sent[0].msg.data == bytes([0x00] * 14)