diff --git a/src/chipid.c b/src/chipid.c
index 92daeb2..2c92d1e 100644
--- a/src/chipid.c
+++ b/src/chipid.c
@@ -389,7 +389,7 @@ static const struct stlink_chipid_params devices[] = {
 
 const struct stlink_chipid_params *stlink_chipid_get_params(uint32_t chipid)
 {
-	struct stlink_chipid_params *params = NULL;
+	const struct stlink_chipid_params *params = NULL;
 
 	for (size_t n = 0; n < STLINK_ARRAY_SIZE(devices); n++) {
 		if (devices[n].chip_id == chipid) {
diff --git a/src/common.c b/src/common.c
index e975c0a..e61bc53 100644
--- a/src/common.c
+++ b/src/common.c
@@ -567,7 +567,7 @@ int stlink_cpu_id(stlink_t *sl, cortex_m3_cpuid_t *cpuid) {
  */
 int stlink_load_device_params(stlink_t *sl) {
     ILOG("Loading device parameters....\n");
-    struct stlink_chipid_params *params = NULL;
+    const struct stlink_chipid_params *params = NULL;
     stlink_core_id(sl);
     uint32_t chip_id;
     uint32_t flash_size;