diff --git a/include/asm-x86/acpi.h b/include/asm-x86/acpi.h
index 635d764..35d1743 100644
--- a/include/asm-x86/acpi.h
+++ b/include/asm-x86/acpi.h
@@ -140,6 +140,8 @@
 	    boot_cpu_data.x86_model <= 0x05 &&
 	    boot_cpu_data.x86_mask < 0x0A)
 		return 1;
+	else if (boot_cpu_has(X86_FEATURE_AMDC1E))
+		return 1;
 	else
 		return max_cstate;
 }