diff --git a/src/crab/gba/arm/branch_exchange.cr b/src/crab/gba/arm/branch_exchange.cr
index f68d410..f12ff54 100644
--- a/src/crab/gba/arm/branch_exchange.cr
+++ b/src/crab/gba/arm/branch_exchange.cr
@@ -1,13 +1,9 @@
 module GBA
   module ARM
     def arm_branch_exchange(instr : Word) : Nil
-      rn = bits(instr, 0..3)
-      if bit?(@r[rn], 0)
-        @cpsr.thumb = true
-        set_reg(15, @r[rn])
-      else
-        set_reg(15, @r[rn])
-      end
+      address = @r[bits(instr, 0..3)]
+      @cpsr.thumb = bit?(address, 0)
+      set_reg(15, address)
     end
   end
 end