diff --git a/src/libsigrok-internal.h b/src/libsigrok-internal.h
index 339c43bc..378c86d4 100644
--- a/src/libsigrok-internal.h
+++ b/src/libsigrok-internal.h
@@ -2392,7 +2392,7 @@ struct sr_sw_limits {
 	uint64_t start_time;
 };
 
-SR_PRIV int sr_sw_limits_config_get(struct sr_sw_limits *limits, uint32_t key,
+SR_PRIV int sr_sw_limits_config_get(const struct sr_sw_limits *limits, uint32_t key,
 	GVariant **data);
 SR_PRIV int sr_sw_limits_config_set(struct sr_sw_limits *limits, uint32_t key,
 	GVariant *data);
diff --git a/src/sw_limits.c b/src/sw_limits.c
index 9d80c06b..55ca79da 100644
--- a/src/sw_limits.c
+++ b/src/sw_limits.c
@@ -57,7 +57,7 @@ SR_PRIV void sr_sw_limits_init(struct sr_sw_limits *limits)
  * @param data config item data
  * @return SR_ERR_NA if @p key is not a supported limit, SR_OK otherwise
  */
-SR_PRIV int sr_sw_limits_config_get(struct sr_sw_limits *limits, uint32_t key,
+SR_PRIV int sr_sw_limits_config_get(const struct sr_sw_limits *limits, uint32_t key,
 	GVariant **data)
 {
 	switch (key) {