diff --git a/EngineHacks/SkillSystem/Skills/PreBattleSkills/Thunderstorm/AssembleARM.bat b/EngineHacks/SkillSystem/Skills/PreBattleSkills/Thunderstorm/AssembleARM.bat
new file mode 100644
index 0000000000..43a1b73d28
--- /dev/null
+++ b/EngineHacks/SkillSystem/Skills/PreBattleSkills/Thunderstorm/AssembleARM.bat
@@ -0,0 +1,20 @@
+@echo off
+
+SET startDir=C:\devkitPro\devkitARM\bin\
+
+@rem Assemble into an elf
+SET as="%startDir%arm-none-eabi-as"
+%as% -g -mcpu=arm7tdmi -mthumb-interwork %1 -o "%~n1.elf"
+
+@rem Print symbol table
+SET readelf="%startDir%arm-none-eabi-readelf"
+%readelf% -s "%~n1.elf" > "%~n1.symbols.log"
+
+@rem Extract raw assembly binary (text section) from elf
+SET objcopy="%startDir%arm-none-eabi-objcopy"
+%objcopy% -S "%~n1.elf" -O binary "%~n1.dmp"
+
+echo y | del "%~n1.elf"
+
+echo y | del "%~n1.symbols.log"
+pause
\ No newline at end of file
diff --git a/EngineHacks/SkillSystem/Skills/PreBattleSkills/Thunderstorm/Thunderstorm.dmp b/EngineHacks/SkillSystem/Skills/PreBattleSkills/Thunderstorm/Thunderstorm.dmp
index 1037d705cf..193900892d 100644
Binary files a/EngineHacks/SkillSystem/Skills/PreBattleSkills/Thunderstorm/Thunderstorm.dmp and b/EngineHacks/SkillSystem/Skills/PreBattleSkills/Thunderstorm/Thunderstorm.dmp differ
diff --git a/EngineHacks/SkillSystem/Skills/PreBattleSkills/Thunderstorm/Thunderstorm.s b/EngineHacks/SkillSystem/Skills/PreBattleSkills/Thunderstorm/Thunderstorm.s
index f94661b6dd..ae51099051 100644
--- a/EngineHacks/SkillSystem/Skills/PreBattleSkills/Thunderstorm/Thunderstorm.s
+++ b/EngineHacks/SkillSystem/Skills/PreBattleSkills/Thunderstorm/Thunderstorm.s
@@ -18,9 +18,10 @@ cmp r0, #0
 beq End
 
 @make sure we're in combat (or combat prep)
-ldrb r3, =gBattleData
+ldr r3, =gBattleData
 ldrb r3, [r3]
-cmp r3, #4
+mov r0, #0x4
+tst r3, r0
 beq End
 
 @store attacker weight in r6