diff --git a/hardware/hantek-dso/dso.h b/hardware/hantek-dso/dso.h
index 44c32982..3220b90d 100644
--- a/hardware/hantek-dso/dso.h
+++ b/hardware/hantek-dso/dso.h
@@ -36,7 +36,7 @@
 #define DEFAULT_FRAMESIZE          FRAMESIZE_SMALL
 #define DEFAULT_TIMEBASE           TIME_100us
 #define DEFAULT_TRIGGER_SOURCE     "CH1"
-#define DEFAULT_COUPLING           COUPLING_AC
+#define DEFAULT_COUPLING           COUPLING_DC
 #define DEFAULT_HORIZ_TRIGGERPOS   0.5
 #define DEFAULT_VERT_OFFSET        0.5
 #define DEFAULT_VERT_TRIGGERPOS    0.5