diff --git a/usr.sbin/acpi/acpidump/acpi_user.c b/usr.sbin/acpi/acpidump/acpi_user.c
index 0b2beb2c4ca..d759ea71c8f 100644
--- a/usr.sbin/acpi/acpidump/acpi_user.c
+++ b/usr.sbin/acpi/acpidump/acpi_user.c
@@ -172,7 +172,7 @@ acpi_find_rsd_ptr(void)
 	addr = 0;
 
 	/* Attempt to use kenv or sysctl to find RSD PTR record. */
-	if (kenv(KENV_GET, hint_acpi_0_rsdp, buf, 20) == 0)
+	if (kenv(KENV_GET, hint_acpi_0_rsdp, buf, 20) > 0)
 		addr = strtoul(buf, NULL, 0);
 	if (addr == 0) {
 		len = sizeof(addr);