diff --git a/output/output_binary.c b/output/output_binary.c
index 41a8caee..2e6603d5 100644
--- a/output/output_binary.c
+++ b/output/output_binary.c
@@ -24,24 +24,6 @@
 #include <sigrok.h>
 #include "config.h"
 
-static int event(struct output *o, int event_type, char **data_out,
-		 uint64_t *length_out)
-{
-	/* Prevent compiler warnings. */
-	o = o;
-
-	switch (event_type) {
-	case DF_TRIGGER:
-		/* TODO? Ignore? */
-		break;
-	case DF_END:
-		*data_out = NULL;
-		*length_out = 0;
-		break;
-	}
-
-	return SIGROK_OK;
-}
 
 static int data(struct output *o, char *data_in, uint64_t length_in,
 		char **data_out, uint64_t *length_out)
@@ -67,5 +49,5 @@ struct output_format output_binary = {
 	DF_LOGIC,
 	NULL,
 	data,
-	event,
+	NULL,
 };
diff --git a/output/output_gnuplot.c b/output/output_gnuplot.c
index 94c566fa..5ad9cc5b 100644
--- a/output/output_gnuplot.c
+++ b/output/output_gnuplot.c
@@ -127,16 +127,17 @@ static int event(struct output *o, int event_type, char **data_out,
 	ctx = o->internal;
 	switch (event_type) {
 	case DF_TRIGGER:
-		/* TODO */
+		/* TODO: can a trigger mark be in a gnuplot data file? */
 		break;
 	case DF_END:
-		*data_out = NULL;
-		*length_out = 0;
 		free(o->internal);
 		o->internal = NULL;
 		break;
 	}
 
+	*data_out = NULL;
+	*length_out = 0;
+
 	return SIGROK_OK;
 }
 
diff --git a/output/output_vcd.c b/output/output_vcd.c
index 190e9e45..34b150d4 100644
--- a/output/output_vcd.c
+++ b/output/output_vcd.c
@@ -135,7 +135,9 @@ static int event(struct output *o, int event_type, char **data_out,
 	ctx = o->internal;
 	switch (event_type) {
 	case DF_TRIGGER:
-		/* TODO */
+		/* TODO: can a trigger mark be in a VCD file? */
+		*data_out = NULL;
+		*length_out = 0;
 		break;
 	case DF_END:
 		outlen = strlen("$dumpoff\n$end\n");
@@ -149,6 +151,10 @@ static int event(struct output *o, int event_type, char **data_out,
 		free(o->internal);
 		o->internal = NULL;
 		break;
+	default:
+		*data_out = NULL;
+		*length_out = 0;
+		break;
 	}
 
 	return SIGROK_OK;