diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index f2abd88e0c254d..91dcfc5a8de347 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -1109,7 +1109,7 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
 	}
 
 	if (cpu_to_chip_id(boot_cpuid) != -1) {
-		int idx = num_possible_cpus() / threads_per_core;
+		int idx = max((int)num_possible_cpus() / threads_per_core, 1);
 
 		/*
 		 * All threads of a core will all belong to the same core,