diff --git a/desmume/src/GPU.cpp b/desmume/src/GPU.cpp
index d536b8ffd..318e602bb 100644
--- a/desmume/src/GPU.cpp
+++ b/desmume/src/GPU.cpp
@@ -65,7 +65,7 @@ OSDCLASS	*osd = NULL;
 OSDCLASS	*osdA = NULL;
 OSDCLASS	*osdB = NULL;
 
-short sizeTab[4][4][2] =
+const short sizeTab[4][4][2] =
 {
       {{256,256}, {512, 256}, {256, 512}, {512, 512}},
       {{128,128}, {256, 256}, {512, 512}, {1024, 1024}},
@@ -74,7 +74,7 @@ short sizeTab[4][4][2] =
 //      {{0, 0}, {0, 0}, {0, 0}, {0, 0}}
 };
 
-size sprSizeTab[4][4] = 
+const size sprSizeTab[4][4] = 
 {
      {{8, 8}, {16, 8}, {8, 16}, {8, 8}},
      {{16, 16}, {32, 8}, {8, 32}, {8, 8}},
@@ -82,7 +82,7 @@ size sprSizeTab[4][4] =
      {{64, 64}, {64, 32}, {32, 64}, {8, 8}},
 };
 
-s8 mode2type[8][4] = 
+const s8 mode2type[8][4] = 
 {
       {0, 0, 0, 0},
       {0, 0, 0, 1},
diff --git a/desmume/src/GPU.h b/desmume/src/GPU.h
index 781a49574..d357252c2 100644
--- a/desmume/src/GPU.h
+++ b/desmume/src/GPU.h
@@ -700,9 +700,9 @@ void extRotBG(GPU * gpu, u8 num, u8 * DST);
 void sprite1D(GPU * gpu, u16 l, u8 * dst, u8 * prioTab);
 void sprite2D(GPU * gpu, u16 l, u8 * dst, u8 * prioTab);
 
-extern short sizeTab[4][4][2];
-extern size sprSizeTab[4][4];
-extern s8 mode2type[8][4];
+extern const short sizeTab[4][4][2];
+extern const size sprSizeTab[4][4];
+extern const s8 mode2type[8][4];
 extern void (*modeRender[8][4])(GPU * gpu, u8 num, u16 l, u8 * DST);
 
 typedef struct {
diff --git a/desmume/src/gtk/main.cpp b/desmume/src/gtk/main.cpp
index 94d94a836..bb15e6eb6 100644
--- a/desmume/src/gtk/main.cpp
+++ b/desmume/src/gtk/main.cpp
@@ -69,7 +69,7 @@ static void Pause();
 static void Printscreen();
 static void Reset();
 
-static GtkActionEntry action_entries[] = {
+static const GtkActionEntry action_entries[] = {
 	{ "open",	"gtk-open",		"Open",		"<Ctrl>o",	NULL,	G_CALLBACK(Open_Select) },
 	{ "run",	"gtk-media-play",	"Run",		"<Ctrl>r",	NULL,	G_CALLBACK(Launch) },
 	{ "pause",	"gtk-media-pause",	"Pause",	"<Ctrl>p",	NULL,	G_CALLBACK(Pause) },