diff --git a/cputree.c b/cputree.c
index fb51a63..af4fd3a 100644
--- a/cputree.c
+++ b/cputree.c
@@ -324,7 +324,7 @@ static void clear_obj_stats(struct topo_obj *d, void *data __attribute__((unused
  * which level does how much work and the actual lists of interrupts 
  * assigned to each component
  */
-void clear_work_stats()
+void clear_work_stats(void)
 {
 	for_each_object(numa_nodes, clear_obj_stats, NULL);
 }
diff --git a/irqbalance.c b/irqbalance.c
index 5bab859..e5b70dc 100644
--- a/irqbalance.c
+++ b/irqbalance.c
@@ -132,21 +132,21 @@ static void parse_command_line(int argc, char **argv)
  * Object workload is the aggregate sum of the
  * workload of the objects below it
  */
-static void build_object_tree()
+static void build_object_tree(void)
 {
 	build_numa_node_list();
 	parse_cpu_tree();
 	rebuild_irq_db();
 }
 
-static void free_object_tree()
+static void free_object_tree(void)
 {
 	free_numa_node_list();
 	clear_cpu_tree();
 	free_irq_db();
 }
 
-static void dump_object_tree()
+static void dump_object_tree(void)
 {
 	for_each_object(numa_nodes, dump_numa_node_info, NULL);
 }
diff --git a/placement.c b/placement.c
index 113891b..108ccc9 100644
--- a/placement.c
+++ b/placement.c
@@ -181,7 +181,7 @@ static void validate_object(struct topo_obj *d, void *data __attribute__((unused
 		for_each_irq(d->interrupts, validate_irq, d);
 }
 
-static void validate_object_tree_placement()
+static void validate_object_tree_placement(void)
 {
 	for_each_object(packages, validate_object, NULL);	
 	for_each_object(cache_domains, validate_object, NULL);
diff --git a/procinterrupts.c b/procinterrupts.c
index 10e7700..2968dfd 100644
--- a/procinterrupts.c
+++ b/procinterrupts.c
@@ -184,7 +184,7 @@ static void reset_load(struct topo_obj *d, void *data __attribute__((unused)))
 	d->load = 0;
 }
 
-void parse_proc_stat()
+void parse_proc_stat(void)
 {
 	FILE *file;
 	char *line = NULL;