diff --git a/CHANGES b/CHANGES
index 0a9efc828..2d6c8d2db 100644
--- a/CHANGES
+++ b/CHANGES
@@ -30,6 +30,7 @@ Other fixes:
  - Qt: Fix corrupted savestate and fatal error text
 Misc:
  - Core: Suspend runloop when a core crashes
+ - GBA I/O: Update KEYINPUT in internal I/O memory (fixes mgba.io/i/2235)
  - mGUI: Add margin to right-aligned menu text (fixes mgba.io/i/871)
  - Qt: Rearrange menus some
  - Qt: Clean up cheats dialog
diff --git a/src/gba/io.c b/src/gba/io.c
index cc39e1192..7abf28047 100644
--- a/src/gba/io.c
+++ b/src/gba/io.c
@@ -763,8 +763,9 @@ uint16_t GBAIORead(struct GBA* gba, uint32_t address) {
 					}
 				}
 			}
-			return 0x3FF ^ input;
+			gba->memory.io[address >> 1] = 0x3FF ^ input;
 		}
+		break;
 	case REG_SIOCNT:
 		return gba->sio.siocnt;
 	case REG_RCNT: