diff --git a/drivers/counter/ftm-quaddec.c b/drivers/counter/ftm-quaddec.c
index c2b3fdfd8b77..9371532406ca 100644
--- a/drivers/counter/ftm-quaddec.c
+++ b/drivers/counter/ftm-quaddec.c
@@ -162,7 +162,7 @@ enum ftm_quaddec_synapse_action {
 	FTM_QUADDEC_SYNAPSE_ACTION_BOTH_EDGES,
 };
 
-static enum counter_synapse_action ftm_quaddec_synapse_actions[] = {
+static const enum counter_synapse_action ftm_quaddec_synapse_actions[] = {
 	[FTM_QUADDEC_SYNAPSE_ACTION_BOTH_EDGES] =
 	COUNTER_SYNAPSE_ACTION_BOTH_EDGES
 };