diff --git a/openbsc/include/openbsc/debug.h b/openbsc/include/openbsc/debug.h
index 24f45add7..c8c0013d9 100644
--- a/openbsc/include/openbsc/debug.h
+++ b/openbsc/include/openbsc/debug.h
@@ -21,6 +21,7 @@
 #define DINP		0x8000
 
 #define DSCCP		0x10000
+#define DMSC		0x20000
 
 #ifdef DEBUG
 #define DEBUGP(ss, fmt, args...) debugp(ss, __FILE__, __LINE__, 0, fmt, ## args)
diff --git a/openbsc/src/debug.c b/openbsc/src/debug.c
index 14d6b603e..f88a90475 100644
--- a/openbsc/src/debug.c
+++ b/openbsc/src/debug.c
@@ -58,6 +58,7 @@ static const struct debug_info debug_info[] = {
 	DEBUG_CATEGORY(DMUX,  "DMUX", "", "")
 	DEBUG_CATEGORY(DMEAS,  "DMEAS", "", "")
 	DEBUG_CATEGORY(DSCCP, "DSCCP", "", "")
+	DEBUG_CATEGORY(DMSC, "DMSC", "", "")
 };
 
 static int use_color = 1;