diff --git a/src/boards/341.c b/src/boards/341.c
index c776544..415a538 100644
--- a/src/boards/341.c
+++ b/src/boards/341.c
@@ -21,7 +21,7 @@
 #include "mapinc.h"
 #include "asic_latch.h"
 
-uint8 submapper;
+static uint8 submapper;
 
 static void sync () {
 	setprg32(0x8000, Latch_address >>8);
diff --git a/src/boards/449.c b/src/boards/449.c
index c1fea0a..21f899e 100644
--- a/src/boards/449.c
+++ b/src/boards/449.c
@@ -21,7 +21,7 @@
 #include "mapinc.h"
 #include "asic_latch.h"
 
-uint8 submapper;
+static uint8 submapper;
 uint8 pad;
 uint8 padSelect;