diff --git a/CHANGES b/CHANGES
index 9debf781f..ad24f9fae 100644
--- a/CHANGES
+++ b/CHANGES
@@ -62,6 +62,7 @@ Misc:
  - Qt: Add load alternate save option
  - GB Audio: Improved audio quality
  - GB, GBA Audio: Increase max audio volume
+ - GB: Fix VRAM/palette locking (fixes mgba.io/i/1109)
 
 0.6.3: (2017-04-14)
 Bugfixes:
diff --git a/src/gb/io.c b/src/gb/io.c
index 14e3b3621..75a292235 100644
--- a/src/gb/io.c
+++ b/src/gb/io.c
@@ -489,8 +489,10 @@ void GBIOWrite(struct GB* gb, unsigned address, uint8_t value) {
 				gb->memory.io[REG_BCPD] = gb->video.palette[gb->video.bcpIndex >> 1] >> (8 * (gb->video.bcpIndex & 1));
 				break;
 			case REG_BCPD:
-				GBVideoProcessDots(&gb->video, 0);
-				GBVideoWritePalette(&gb->video, address, value);
+				if (gb->video.mode != 3) {
+					GBVideoProcessDots(&gb->video, 0);
+					GBVideoWritePalette(&gb->video, address, value);
+				}
 				return;
 			case REG_OCPS:
 				gb->video.ocpIndex = value & 0x3F;
@@ -498,8 +500,10 @@ void GBIOWrite(struct GB* gb, unsigned address, uint8_t value) {
 				gb->memory.io[REG_OCPD] = gb->video.palette[8 * 4 + (gb->video.ocpIndex >> 1)] >> (8 * (gb->video.ocpIndex & 1));
 				break;
 			case REG_OCPD:
-				GBVideoProcessDots(&gb->video, 0);
-				GBVideoWritePalette(&gb->video, address, value);
+				if (gb->video.mode != 3) {
+					GBVideoProcessDots(&gb->video, 0);
+					GBVideoWritePalette(&gb->video, address, value);
+				}
 				return;
 			case REG_SVBK:
 				GBMemorySwitchWramBank(&gb->memory, value);
diff --git a/src/gb/memory.c b/src/gb/memory.c
index 799234ae4..8b2a873f8 100644
--- a/src/gb/memory.c
+++ b/src/gb/memory.c
@@ -239,7 +239,10 @@ uint8_t GBLoad8(struct LR35902Core* cpu, uint16_t address) {
 		return memory->romBank[address & (GB_SIZE_CART_BANK0 - 1)];
 	case GB_REGION_VRAM:
 	case GB_REGION_VRAM + 1:
-		return gb->video.vramBank[address & (GB_SIZE_VRAM_BANK0 - 1)];
+		if (gb->video.mode != 3) {
+			return gb->video.vramBank[address & (GB_SIZE_VRAM_BANK0 - 1)];
+		}
+		return 0xFF;
 	case GB_REGION_EXTERNAL_RAM:
 	case GB_REGION_EXTERNAL_RAM + 1:
 		if (memory->rtcAccess) {
@@ -309,8 +312,10 @@ void GBStore8(struct LR35902Core* cpu, uint16_t address, int8_t value) {
 		return;
 	case GB_REGION_VRAM:
 	case GB_REGION_VRAM + 1:
-		gb->video.renderer->writeVRAM(gb->video.renderer, (address & (GB_SIZE_VRAM_BANK0 - 1)) | (GB_SIZE_VRAM_BANK0 * gb->video.vramCurrentBank));
-		gb->video.vramBank[address & (GB_SIZE_VRAM_BANK0 - 1)] = value;
+		if (gb->video.mode != 3) {
+			gb->video.renderer->writeVRAM(gb->video.renderer, (address & (GB_SIZE_VRAM_BANK0 - 1)) | (GB_SIZE_VRAM_BANK0 * gb->video.vramCurrentBank));
+			gb->video.vramBank[address & (GB_SIZE_VRAM_BANK0 - 1)] = value;
+		}
 		return;
 	case GB_REGION_EXTERNAL_RAM:
 	case GB_REGION_EXTERNAL_RAM + 1: