diff --git a/src/arm.c b/src/arm.c
index 4d5deeca6..995c879fe 100644
--- a/src/arm.c
+++ b/src/arm.c
@@ -389,6 +389,7 @@ DEFINE_INSTRUCTION_ARM(MSR,)
 DEFINE_INSTRUCTION_ARM(MRS,)
 DEFINE_INSTRUCTION_ARM(MSRI,)
 DEFINE_INSTRUCTION_ARM(MRSI,)
+DEFINE_INSTRUCTION_ARM(SWI,)
 
 #define DECLARE_INSTRUCTION_ARM(COND, NAME) \
 	_ARMInstruction ## NAME ## COND
@@ -403,6 +404,12 @@ DEFINE_INSTRUCTION_ARM(MRSI,)
 	DIRECTIVE, \
 	DIRECTIVE
 
+#define DO_256(DIRECTIVE) \
+	DO_8(DO_8(DIRECTIVE)), \
+	DO_8(DO_8(DIRECTIVE)), \
+	DO_8(DO_8(DIRECTIVE)), \
+	DO_8(DO_8(DIRECTIVE))
+
 #define DO_INTERLACE(LEFT, RIGHT) \
 	LEFT, \
 	RIGHT
@@ -449,10 +456,7 @@ DEFINE_INSTRUCTION_ARM(MRSI,)
 	DO_8(DECLARE_INSTRUCTION_ARM(COND, NAME ## MODE ## W))
 
 #define DECLARE_ARM_BRANCH_BLOCK(COND, NAME) \
-	DO_8(DO_8(DECLARE_INSTRUCTION_ARM(COND, NAME))), \
-	DO_8(DO_8(DECLARE_INSTRUCTION_ARM(COND, NAME))), \
-	DO_8(DO_8(DECLARE_INSTRUCTION_ARM(COND, NAME))), \
-	DO_8(DO_8(DECLARE_INSTRUCTION_ARM(COND, NAME)))
+	DO_256(DECLARE_INSTRUCTION_ARM(COND, NAME))
 
 // TODO: Support coprocessors
 #define DECLARE_ARM_LOAD_STORE_COPROCESSOR_BLOCK(COND, NAME, P, U, W, N) \
@@ -463,6 +467,9 @@ DEFINE_INSTRUCTION_ARM(MRSI,)
 	DO_8(DO_8(DO_INTERLACE(0, 0))), \
 	DO_8(DO_8(DO_INTERLACE(0, 0)))
 
+#define DECLARE_ARM_SWI_BLOCK(COND) \
+	DO_256(DECLARE_INSTRUCTION_ARM(COND, SWI))
+
 #define DECLARE_COND_BLOCK(COND) \
 	DECLARE_ARM_ALU_BLOCK(COND, AND, MUL, STRH, ILL, ILL), \
 	DECLARE_ARM_ALU_BLOCK(COND, ANDS, MULS, LDRH, LDRSB, LDRSH), \
@@ -673,8 +680,8 @@ DEFINE_INSTRUCTION_ARM(MRSI,)
 	DECLARE_ARM_LOAD_STORE_COPROCESSOR_BLOCK(COND, LDC, P, U, N, ), \
 	DECLARE_ARM_LOAD_STORE_COPROCESSOR_BLOCK(COND, STC, P, U, N, W), \
 	DECLARE_ARM_LOAD_STORE_COPROCESSOR_BLOCK(COND, LDC, P, U, N, W), \
-	DECLARE_ARM_COPROCESSOR_BLOCK(COND, CDP, MCR)//, \
-	// DECLARE_ARM_SWI_BLOCK
+	DECLARE_ARM_COPROCESSOR_BLOCK(COND, CDP, MCR), \
+	DECLARE_ARM_SWI_BLOCK(COND)
 
 static const ARMInstruction armTable[0x10000] = {
 	DECLARE_COND_BLOCK(EQ),