diff --git a/sys/dev/acpica/acpi_spmc.c b/sys/dev/acpica/acpi_spmc.c
--- a/sys/dev/acpica/acpi_spmc.c
+++ b/sys/dev/acpica/acpi_spmc.c
@@ -474,8 +474,8 @@
 	for (size_t i = 0; i < sc->constraint_count; i++) {
 		constraint = &sc->constraints[i];
 
-		status = acpi_GetHandleInScope(sc->handle,
-		    __DECONST(char *, constraint->name), &constraint->handle);
+		status = acpi_GetHandleInScope(sc->handle, constraint->name,
+		    &constraint->handle);
 		if (ACPI_FAILURE(status)) {
 			device_printf(dev, "failed to get handle for %s\n",
 			    constraint->name);
@@ -500,7 +500,7 @@
 			continue;
 
 		ACPI_STATUS status = acpi_GetHandleInScope(sc->handle,
-		    __DECONST(char *, constraint->name), &constraint->handle);
+		    constraint->name, &constraint->handle);
 		if (ACPI_FAILURE(status)) {
 			device_printf(sc->dev, "failed to get handle for %s\n",
 			    constraint->name);