diff --git a/doc/pr-changelogs/3397.md b/doc/pr-changelogs/3397.md
new file mode 100644
index 0000000000..058d7e4527
--- /dev/null
+++ b/doc/pr-changelogs/3397.md
@@ -0,0 +1 @@
+* add `subMissile` boolean export to the Lua weaponDefs. Non-torpedo weapon types always have subMissile=false.
\ No newline at end of file
diff --git a/rts/Lua/LuaWeaponDefs.cpp b/rts/Lua/LuaWeaponDefs.cpp
index b2815d8cf7..fc57f18fba 100644
--- a/rts/Lua/LuaWeaponDefs.cpp
+++ b/rts/Lua/LuaWeaponDefs.cpp
@@ -519,6 +519,7 @@ static bool InitParamMap()
 	ADD_BOOL("turret", wd.turret);
 	ADD_BOOL("onlyForward", wd.onlyForward);
 	ADD_BOOL("waterWeapon", wd.waterweapon);
+	ADD_BOOL("subMissile", wd.submissile);
 	ADD_BOOL("tracks", wd.tracks);
 	ADD_BOOL("paralyzer", wd.paralyzer);
 
diff --git a/rts/Sim/Weapons/WeaponDef.cpp b/rts/Sim/Weapons/WeaponDef.cpp
index 7dbd55a08c..a5468060d4 100644
--- a/rts/Sim/Weapons/WeaponDef.cpp
+++ b/rts/Sim/Weapons/WeaponDef.cpp
@@ -570,6 +570,7 @@ WeaponDef::WeaponDef(const LuaTable& wdTable, const std::string& name_, int id_)
 	isShield = (type == "Shield");
 	noAutoTarget = (manualfire || interceptor || isShield);
 	onlyForward = !turret && (projectileType != WEAPON_STARBURST_PROJECTILE);
+	submissile &= (projectileType == WEAPON_TORPEDO_PROJECTILE);
 }