diff --git a/include/asm-generic/percpu.h b/include/asm-generic/percpu.h
index 3b709b84934f..9044aeb37828 100644
--- a/include/asm-generic/percpu.h
+++ b/include/asm-generic/percpu.h
@@ -29,7 +29,7 @@ do {								\
 #define DEFINE_PER_CPU(type, name) \
     __typeof__(type) per_cpu__##name
 
-#define per_cpu(var, cpu)			(*((void)cpu, &per_cpu__##var))
+#define per_cpu(var, cpu)			(*((void)(cpu), &per_cpu__##var))
 #define __get_cpu_var(var)			per_cpu__##var
 
 #endif	/* SMP */
diff --git a/include/asm-ia64/percpu.h b/include/asm-ia64/percpu.h
index 1e87f19dad56..2b14dee29ce7 100644
--- a/include/asm-ia64/percpu.h
+++ b/include/asm-ia64/percpu.h
@@ -50,7 +50,7 @@ extern void *per_cpu_init(void);
 
 #else /* ! SMP */
 
-#define per_cpu(var, cpu)			(*((void)cpu, &per_cpu__##var))
+#define per_cpu(var, cpu)			(*((void)(cpu), &per_cpu__##var))
 #define __get_cpu_var(var)			per_cpu__##var
 #define per_cpu_init()				(__phys_per_cpu_start)
 
diff --git a/include/asm-x86_64/percpu.h b/include/asm-x86_64/percpu.h
index 415d73f3c8ef..9c71855736fb 100644
--- a/include/asm-x86_64/percpu.h
+++ b/include/asm-x86_64/percpu.h
@@ -39,7 +39,7 @@ extern void setup_per_cpu_areas(void);
 #define DEFINE_PER_CPU(type, name) \
     __typeof__(type) per_cpu__##name
 
-#define per_cpu(var, cpu)			(*((void)cpu, &per_cpu__##var))
+#define per_cpu(var, cpu)			(*((void)(cpu), &per_cpu__##var))
 #define __get_cpu_var(var)			per_cpu__##var
 
 #endif	/* SMP */