diff --git a/arch/s390/include/asm/topology.h b/arch/s390/include/asm/topology.h
index c979c3b..5e0ad61 100644
--- a/arch/s390/include/asm/topology.h
+++ b/arch/s390/include/asm/topology.h
@@ -5,7 +5,6 @@
 
 #define mc_capable()	(1)
 
-cpumask_t cpu_coregroup_map(unsigned int cpu);
 const struct cpumask *cpu_coregroup_mask(unsigned int cpu);
 
 extern cpumask_t cpu_core_map[NR_CPUS];
diff --git a/arch/s390/kernel/topology.c b/arch/s390/kernel/topology.c
index cc362c9..3c72c9c 100644
--- a/arch/s390/kernel/topology.c
+++ b/arch/s390/kernel/topology.c
@@ -74,7 +74,7 @@
 
 cpumask_t cpu_core_map[NR_CPUS];
 
-cpumask_t cpu_coregroup_map(unsigned int cpu)
+static cpumask_t cpu_coregroup_map(unsigned int cpu)
 {
 	struct core_info *core = &core_info;
 	unsigned long flags;