diff --git a/src/arm/isa-arm.c b/src/arm/isa-arm.c
index e174eb1e8..5ff459814 100644
--- a/src/arm/isa-arm.c
+++ b/src/arm/isa-arm.c
@@ -663,7 +663,7 @@ DEFINE_INSTRUCTION_ARM(MSRRI,
 	mask &= PSR_USER_MASK | PSR_PRIV_MASK | PSR_STATE_MASK;
 	cpu->spsr.packed = (cpu->spsr.packed & ~mask) | (operand & mask);)
 
-DEFINE_INSTRUCTION_ARM(SWI, ARM_STUB)
+DEFINE_INSTRUCTION_ARM(SWI, cpu->board->swi32(cpu->board, opcode & 0xFFFFFF))
 
 #define DECLARE_INSTRUCTION_ARM(EMITTER, NAME) \
 	EMITTER ## NAME
diff --git a/src/gba/gba-bios.c b/src/gba/gba-bios.c
index 8c43b32dc..2d7023054 100644
--- a/src/gba/gba-bios.c
+++ b/src/gba/gba-bios.c
@@ -134,7 +134,7 @@ void GBASwi16(struct ARMBoard* board, int immediate) {
 }
 
 void GBASwi32(struct ARMBoard* board, int immediate) {
-	GBASwi32(board, immediate >> 16);
+	GBASwi16(board, immediate >> 16);
 }
 
 static void _unLz77(struct GBAMemory* memory, uint32_t source, uint8_t* dest) {