diff --git a/common.h b/common.h
index 6299200..f67a999 100644
--- a/common.h
+++ b/common.h
@@ -34,7 +34,7 @@
 #define SEM_USED_SPACE "/used_space_01527193"
 #define SEM_WRITE_END "/write_end_01527193"
 
-#define MAX_ITEMS 16
+#define MAX_ITEMS 32
 
 struct circ_buf {
 	int quit;
diff --git a/generator.c b/generator.c
index 72b4d73..9bdfea7 100644
--- a/generator.c
+++ b/generator.c
@@ -15,11 +15,11 @@ static struct circ_buf *shared;
 
 int shmfd;
 
-sem_t *sUsedSpace;
+static sem_t *sUsedSpace;
 
-sem_t *sFreeSpace;
+static sem_t *sFreeSpace;
 
-sem_t *sWriteEnd;
+static sem_t *sWriteEnd;
 
 struct sigaction sa;
 
diff --git a/supervisor.c b/supervisor.c
index 3e8390d..4fbebaa 100644
--- a/supervisor.c
+++ b/supervisor.c
@@ -14,11 +14,11 @@ struct circ_buf *shared;
 
 int shmfd;
 
-sem_t *sUsedSpace;
+static sem_t *sUsedSpace;
 
-sem_t *sFreeSpace;
+static sem_t *sFreeSpace;
 
-sem_t *sWriteEnd;
+static sem_t *sWriteEnd;
 
 struct sigaction sa;