diff --git a/src/gba/gba-io.c b/src/gba/gba-io.c
index 47fda35c9..3cc49113c 100644
--- a/src/gba/gba-io.c
+++ b/src/gba/gba-io.c
@@ -3,7 +3,16 @@
 void GBAIOWrite(struct GBA* gba, uint32_t address, uint16_t value) {
 	switch (address) {
 	default:
-		GBALog(GBA_LOG_STUB, "Stub I/O register: %03x", address);
+		GBALog(GBA_LOG_STUB, "Stub I/O register write: %03x", address);
 		break;
 	}
 }
+
+uint16_t GBAIORead(struct GBA* gba, uint32_t address) {
+	switch (address) {
+	default:
+		GBALog(GBA_LOG_STUB, "Stub I/O register read: %03x", address);
+		break;
+	}
+	return 0;
+}
diff --git a/src/gba/gba-io.h b/src/gba/gba-io.h
index ad3cd77bc..9cb319b24 100644
--- a/src/gba/gba-io.h
+++ b/src/gba/gba-io.h
@@ -142,5 +142,6 @@ enum GBAIORegisters {
 };
 
 void GBAIOWrite(struct GBA* gba, uint32_t address, uint16_t value);
+uint16_t GBAIORead(struct GBA* gba, uint32_t address);
 
 #endif
diff --git a/src/gba/gba-memory.c b/src/gba/gba-memory.c
index 1dfa6daab..65155dd72 100644
--- a/src/gba/gba-memory.c
+++ b/src/gba/gba-memory.c
@@ -137,7 +137,7 @@ int16_t GBALoad16(struct ARMMemory* memory, uint32_t address) {
 	case BASE_WORKING_IRAM:
 		return ((int16_t*) gbaMemory->iwram)[(address & (SIZE_WORKING_IRAM - 1)) >> 1];
 	case BASE_IO:
-		break;
+		return GBAIORead(gbaMemory->p, address & (SIZE_IO - 1));
 	case BASE_PALETTE_RAM:
 		break;
 	case BASE_VRAM:
@@ -171,7 +171,7 @@ uint16_t GBALoadU16(struct ARMMemory* memory, uint32_t address) {
 	case BASE_WORKING_IRAM:
 		return ((uint16_t*) gbaMemory->iwram)[(address & (SIZE_WORKING_IRAM - 1)) >> 1];
 	case BASE_IO:
-		break;
+		return GBAIORead(gbaMemory->p, address & (SIZE_IO - 1));
 	case BASE_PALETTE_RAM:
 		break;
 	case BASE_VRAM: