diff --git a/CHANGES b/CHANGES
index 40acf4c1a..400c429fd 100644
--- a/CHANGES
+++ b/CHANGES
@@ -84,6 +84,7 @@ Misc:
  - Core: Rework thread state synchronization
  - GB: Allow pausing event loop while CPU is blocked
  - GB: Add support for sleep and shutdown callbacks
+ - GB I/O: Implement preliminary support for PCM12/PCM34 (closes mgba.io/i/1468)
  - GBA: Allow pausing event loop while CPU is blocked
  - GBA BIOS: Division by zero should emit a FATAL error
  - GBA Video: Convert OpenGL VRAM texture to integer
diff --git a/src/gb/io.c b/src/gb/io.c
index c0a2d36cc..0e3a70eca 100644
--- a/src/gb/io.c
+++ b/src/gb/io.c
@@ -216,7 +216,7 @@ void GBIOReset(struct GB* gb) {
 		GBIOWrite(gb, GB_REG_HDMA4, 0xFF);
 		gb->memory.io[GB_REG_HDMA5] = 0xFF;
 	} else {
-		memset(&gb->memory.io[GB_REG_KEY0], 0xFF, GB_REG_PCM34 - GB_REG_KEY0);
+		memset(&gb->memory.io[GB_REG_KEY0], 0xFF, GB_REG_PCM34 - GB_REG_KEY0 + 1);
 	}
 
 	if (gb->model & GB_MODEL_SGB) {
@@ -622,6 +622,20 @@ uint8_t GBIORead(struct GB* gb, unsigned address) {
 			return gb->audio.ch3.wavedata8[address - GB_REG_WAVE_0];
 		}
 		break;
+	case GB_REG_PCM12:
+		if (gb->model < GB_MODEL_CGB) {
+			mLOG(GB_IO, GAME_ERROR, "Reading from CGB register FF%02X in DMG mode", address);
+		} else if (gb->audio.enable) {
+			return (gb->audio.ch1.sample) | (gb->audio.ch2.sample << 4);
+		}
+		break;
+	case GB_REG_PCM34:
+		if (gb->model < GB_MODEL_CGB) {
+			mLOG(GB_IO, GAME_ERROR, "Reading from CGB register FF%02X in DMG mode", address);
+		} else if (gb->audio.enable) {
+			return (gb->audio.ch3.sample) | (gb->audio.ch4.sample << 4);
+		}
+		break;
 	case GB_REG_SB:
 	case GB_REG_SC:
 	case GB_REG_IF: