diff --git a/util/ectool.c b/util/ectool.c
index bc6353640a..d42c6941f3 100644
--- a/util/ectool.c
+++ b/util/ectool.c
@@ -1688,6 +1688,14 @@ int cmd_thermal_set_threshold(int argc, char *argv[])
 static int get_num_fans(void)
 {
 	int idx, rv;
+	struct ec_response_get_features r;
+
+	rv = ec_command(EC_CMD_GET_FEATURES, 0, NULL, 0, &r, sizeof(r));
+	if (rv < 0)
+		return rv;
+
+	if (!(r.flags[0] & (1 << EC_FEATURE_PWM_FAN)))
+		return 0;
 
 	for (idx = 0; idx < EC_FAN_SPEED_ENTRIES; idx++) {
 		rv = read_mapped_mem16(EC_MEMMAP_FAN + 2 * idx);