diff --git a/include/mgba/internal/gb/io.h b/include/mgba/internal/gb/io.h
index ada06dcb1..172b93f41 100644
--- a/include/mgba/internal/gb/io.h
+++ b/include/mgba/internal/gb/io.h
@@ -100,7 +100,6 @@ enum GBIORegisters {
 	GB_REG_OCPD = 0x6B,
 	GB_REG_OPRI = 0x6C,
 	GB_REG_SVBK = 0x70,
-	GB_REG_PSM = 0x71,
 	GB_REG_PSWX = 0x72,
 	GB_REG_PSWY = 0x73,
 	GB_REG_PSW = 0x74,
diff --git a/src/gb/io.c b/src/gb/io.c
index affa99a51..61a1b7c93 100644
--- a/src/gb/io.c
+++ b/src/gb/io.c
@@ -687,10 +687,8 @@ uint8_t GBIORead(struct GB* gb, unsigned address) {
 	case GB_REG_OCPS:
 	case GB_REG_OCPD:
 	case GB_REG_SVBK:
-	case GB_REG_PSM:
 	case GB_REG_PSWX:
 	case GB_REG_PSWY:
-	case GB_REG_PSW:
 	case GB_REG_UNK75:
 		// Handled transparently by the registers
 		if (gb->model < GB_MODEL_CGB) {