diff --git a/picoscope/ps5000a.py b/picoscope/ps5000a.py
index 6ff545d..2ed5350 100644
--- a/picoscope/ps5000a.py
+++ b/picoscope/ps5000a.py
@@ -176,7 +176,7 @@ def _lowLevelOpenUnit(self, sn):
             self.AWGMaxVal = 32767
             self.AWGMinVal = -32768
             self.AWGMaxSamples = 49152
-        elif self.model in ('5243B', '5443B'):
+        elif self.model in ('5243B', '5443B', '5243D', '5443D'):
             self.AWGBufferAddressWidth = 15
             self.AWGMaxVal = 32767
             self.AWGMinVal = -32768