diff --git a/check/mode-common.c b/check/mode-common.c
index 6f3ea001..0467ba28 100644
--- a/check/mode-common.c
+++ b/check/mode-common.c
@@ -587,7 +587,7 @@ int check_child_node(struct extent_buffer *parent, int slot,
 	return ret;
 }
 
-void reset_cached_block_groups()
+void reset_cached_block_groups(void)
 {
 	struct btrfs_block_group *cache;
 	u64 start, end;
diff --git a/tune/main.c b/tune/main.c
index bec89690..b0509cf1 100644
--- a/tune/main.c
+++ b/tune/main.c
@@ -166,7 +166,7 @@ enum btrfstune_group_enum {
 
 static bool btrfstune_cmd_groups[BTRFSTUNE_NR_GROUPS] = { 0 };
 
-static unsigned int btrfstune_count_set_groups()
+static unsigned int btrfstune_count_set_groups(void)
 {
 	int ret = 0;