diff --git a/src/g_level.cpp b/src/g_level.cpp
index 0b211f3e60..17f76a67d0 100644
--- a/src/g_level.cpp
+++ b/src/g_level.cpp
@@ -2028,6 +2028,10 @@ DEFINE_FIELD(FLevelLocals, F1Pic)
 DEFINE_FIELD(FLevelLocals, maptype)
 DEFINE_FIELD(FLevelLocals, Music)
 DEFINE_FIELD(FLevelLocals, musicorder)
+DEFINE_FIELD(FLevelLocals, skytexture1)
+DEFINE_FIELD(FLevelLocals, skytexture2)
+DEFINE_FIELD(FLevelLocals, skyspeed1)
+DEFINE_FIELD(FLevelLocals, skyspeed2)
 DEFINE_FIELD(FLevelLocals, total_secrets)
 DEFINE_FIELD(FLevelLocals, found_secrets)
 DEFINE_FIELD(FLevelLocals, total_items)
@@ -2093,3 +2097,19 @@ CCMD(skyfog)
 	}
 }
 
+
+//==========================================================================
+//
+// ZScript counterpart to ACS ChangeSky, uses TextureIDs
+//
+//==========================================================================
+DEFINE_ACTION_FUNCTION(FLevelLocals, ChangeSky)
+{
+	PARAM_SELF_STRUCT_PROLOGUE(FLevelLocals);
+	PARAM_INT(sky1);
+	PARAM_INT(sky2);
+	sky1texture = self->skytexture1 = FSetTextureID(sky1);
+	sky2texture = self->skytexture2 = FSetTextureID(sky2);
+	R_InitSkyMap();
+	return 0;
+}
diff --git a/wadsrc/static/zscript/base.txt b/wadsrc/static/zscript/base.txt
index bef1751da8..503efa453d 100644
--- a/wadsrc/static/zscript/base.txt
+++ b/wadsrc/static/zscript/base.txt
@@ -591,6 +591,10 @@ struct LevelLocals native
 	native readonly int maptype;
 	native readonly String Music;
 	native readonly int musicorder;
+	native readonly TextureID skytexture1;
+	native readonly TextureID skytexture2;
+	native float skyspeed1;
+	native float skyspeed2;
 	native int total_secrets;
 	native int found_secrets;
 	native int total_items;
@@ -640,7 +644,9 @@ struct LevelLocals native
 	native static clearscope vector3 Vec3Diff(vector3 v1, vector3 v2);
 
 	native String GetChecksum() const;
-	
+
+	native void ChangeSky( TextureID sky1, TextureID sky2 );
+
 	String TimeFormatted(bool totals = false)
 	{
 		int sec = Thinker.Tics2Seconds(totals? totaltime : time);