diff --git a/gflib/bg.c b/gflib/bg.c
index 0c702ae0f..ec7c2113b 100644
--- a/gflib/bg.c
+++ b/gflib/bg.c
@@ -246,17 +246,17 @@ static void SetBgAffineInternal(u8 bg, s32 srcCenterX, s32 srcCenterY, s16 dispC
 
     switch (sGpuBgConfigs.bgVisibilityAndMode & 0x7)
     {
+    default:
+    case 0:
+        return;
     case 1:
         if (bg != 2)
             return;
         break;
     case 2:
-        if (bg < 2 || bg >= NUM_BACKGROUNDS)
+        if (bg != 2 && bg != 3)
             return;
         break;
-    case 0:
-    default:
-        return;
     }
 
     src.texX = srcCenterX;
@@ -689,7 +689,7 @@ s32 ChangeBgY(u8 bg, s32 value, u8 op)
     return sGpuBgConfigs2[bg].bg_y;
 }
 
-s32 ChangeBgY_ScreenOff(u8 bg, u32 value, u8 op)
+s32 ChangeBgY_ScreenOff(u8 bg, s32 value, u8 op)
 {
     u8 mode;
     u16 temp1;
diff --git a/gflib/bg.h b/gflib/bg.h
index 3c7eee292..58fd1282c 100644
--- a/gflib/bg.h
+++ b/gflib/bg.h
@@ -59,7 +59,7 @@ u16 GetBgAttribute(u8 bg, u8 attributeId);
 s32 ChangeBgX(u8 bg, s32 value, u8 op);
 s32 GetBgX(u8 bg);
 s32 ChangeBgY(u8 bg, s32 value, u8 op);
-s32 ChangeBgY_ScreenOff(u8 bg, u32 value, u8 op);
+s32 ChangeBgY_ScreenOff(u8 bg, s32 value, u8 op);
 s32 GetBgY(u8 bg);
 void SetBgAffine(u8 bg, s32 srcCenterX, s32 srcCenterY, s16 dispCenterX, s16 dispCenterY, s16 scaleX, s16 scaleY, u16 rotationAngle);
 u8 Unused_AdjustBgMosaic(u8 a1, u8 a2);
diff --git a/src/battle_factory.c b/src/battle_factory.c
index 72772929a..e0bfdfdd0 100644
--- a/src/battle_factory.c
+++ b/src/battle_factory.c
@@ -38,7 +38,7 @@ static void GenerateInitialRentalMons(void);
 static void GetOpponentMostCommonMonType(void);
 static void GetOpponentBattleStyle(void);
 static void RestorePlayerPartyHeldItems(void);
-static u16 GetFactoryMonId(u8 lvlMode, u8 challengeNum, bool8 arg2);
+static u16 GetFactoryMonId(u8 lvlMode, u8 challengeNum, bool8 useBetterRange);
 static u8 GetMoveBattleStyle(u16 move);
 
 // Number of moves needed on the team to be considered using a certain battle style