diff --git a/src/ds/renderers/software.c b/src/ds/renderers/software.c
index 0f5be1e0e..d1399ff75 100644
--- a/src/ds/renderers/software.c
+++ b/src/ds/renderers/software.c
@@ -774,11 +774,11 @@ void DSVideoSoftwareRendererDrawBackgroundExt1(struct GBAVideoSoftwareRenderer*
 
 		if (!mosaicWait) {
 			uint32_t address = (localX >> 8) + (localY >> 8) * width + screenBase;
-			uint8_t* vram = (uint8_t*) renderer->d.vramBG[address >> 17];
+			uint8_t* vram = (uint8_t*) renderer->d.vramBG[address >> VRAM_BLOCK_OFFSET];
 			if (UNLIKELY(!vram)) {
 				continue;
 			}
-			color = vram[address];
+			color = vram[address & VRAM_BLOCK_MASK];
 			mosaicWait = mosaicH;
 		} else {
 			--mosaicWait;
@@ -831,11 +831,11 @@ void DSVideoSoftwareRendererDrawBackgroundExt2(struct GBAVideoSoftwareRenderer*
 
 		if (!mosaicWait) {
 			uint32_t address = ((localX >> 8) + (localY >> 8) * width + screenBase) << 1;
-			uint16_t* vram = renderer->d.vramBG[address >> 17];
+			uint16_t* vram = renderer->d.vramBG[address >> VRAM_BLOCK_OFFSET];
 			if (UNLIKELY(!vram)) {
 				continue;
 			}
-			LOAD_16(color, address & 0x1FFFE, vram);
+			LOAD_16(color, address & VRAM_BLOCK_MASK, vram);
 #ifndef COLOR_16_BIT
 			unsigned color32;
 			color32 = 0;