diff --git a/src/dsd_main.c b/src/dsd_main.c
index 02dececf..8ff463fe 100644
--- a/src/dsd_main.c
+++ b/src/dsd_main.c
@@ -236,6 +236,8 @@ initState (dsd_state * state)
   state->debug_header_errors = 0;
   state->debug_header_critical_errors = 0;
 
+  state->last_dibit = 0;
+
 #ifdef TRACE_DSD
   state->debug_sample_index = 0;
   state->debug_label_file = NULL;