diff --git a/macho-go/pkg/ios/macho/arm.c b/macho-go/pkg/ios/macho/arm.c
index bb82b8b..8842c26 100644
--- a/macho-go/pkg/ios/macho/arm.c
+++ b/macho-go/pkg/ios/macho/arm.c
@@ -43,6 +43,7 @@ struct add {
   uint32_t op : 1;
   uint32_t s : 1;
   uint32_t sig : 5;
+  uint32_t shift : 2;
   uint32_t imm : 12;
   uint32_t rn : 5;
   uint32_t rd : 5;
@@ -54,6 +55,7 @@ struct add to_add(uint32_t inst) {
   parsed.op = is_bit_set(inst, 30);
   parsed.s = is_bit_set(inst, 29);
   parsed.sig = get_bits(inst, 24, 28);
+  parsed.shift = get_bits(inst, 22, 23);
   parsed.imm = get_bits(inst, 10, 21);
   parsed.rn = get_bits(inst, 5, 9);
   parsed.rd = get_bits(inst, 0, 4);
@@ -66,6 +68,7 @@ void from_add(struct add parsed, uint32_t *inst) {
   *inst |= parsed.op << 30;
   *inst |= parsed.s << 29;
   *inst |= parsed.sig << 24;
+  *inst |= parsed.shift << 22;
   *inst |= parsed.imm << 10;
   *inst |= parsed.rn << 5;
   *inst |= parsed.rd;
@@ -83,6 +86,10 @@ int add_imm_set(uint32_t *inst, uint32_t offset) {
 
 uint32_t add_imm_get(uint32_t inst) {
   struct add parsed = to_add(inst);
+  if (parsed.shift != 0) {
+    printf("add instruction shift != 0 is not supported\n");
+    *(char*)0 = 0;
+  }
   return parsed.imm;
 }