diff --git a/arch/i386/kernel/cpu/cpufreq/speedstep-smi.c b/arch/i386/kernel/cpu/cpufreq/speedstep-smi.c
index 79440b3f087e..b25fb6b635ae 100644
--- a/arch/i386/kernel/cpu/cpufreq/speedstep-smi.c
+++ b/arch/i386/kernel/cpu/cpufreq/speedstep-smi.c
@@ -357,6 +357,9 @@ static int __init speedstep_init(void)
 	case SPEEDSTEP_PROCESSOR_PIII_C:
 	case SPEEDSTEP_PROCESSOR_PIII_C_EARLY:
 		break;
+	case SPEEDSTEP_PROCESSOR_P4M:
+		printk(KERN_INFO "speedstep-smi: you're trying to use this cpufreq driver on a Pentium 4-based CPU. Most likely it will not work.\n");
+		break;
 	default:
 		speedstep_processor = 0;
 	}