diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index ddd027c80..2720f026d 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -835,7 +835,6 @@ set( NOT_COMPILED_SOURCE_FILES
 	${OTHER_SYSTEM_SOURCES}
 	sc_man_scanner.h
 	sc_man_scanner.re
-	g_doom/a_arachnotron.cpp
 	g_doom/a_archvile.cpp
 	g_doom/a_bossbrain.cpp
 	g_doom/a_bruiser.cpp
diff --git a/src/g_doom/a_arachnotron.cpp b/src/g_doom/a_arachnotron.cpp
deleted file mode 100644
index 22223d24b..000000000
--- a/src/g_doom/a_arachnotron.cpp
+++ /dev/null
@@ -1,30 +0,0 @@
-/*
-#include "actor.h"
-#include "s_sound.h"
-#include "p_local.h"
-#include "p_enemy.h"
-#include "a_action.h"
-#include "vm.h"
-*/
-
-DEFINE_ACTION_FUNCTION(AActor, A_BspiAttack)
-{
-	PARAM_SELF_PROLOGUE(AActor);
-
-	if (!self->target)
-		return 0;
-
-	A_FaceTarget (self);
-
-	// launch a missile
-	P_SpawnMissile (self, self->target, PClass::FindActor("ArachnotronPlasma"));
-	return 0;
-}
-
-DEFINE_ACTION_FUNCTION(AActor, A_BabyMetal)
-{
-	PARAM_SELF_PROLOGUE(AActor);
-	S_Sound (self, CHAN_BODY, "baby/walk", 1, ATTN_IDLE);
-	A_Chase (stack, self);
-	return 0;
-}
diff --git a/src/g_doom/a_doommisc.cpp b/src/g_doom/a_doommisc.cpp
index a4eca67b7..81e5a253a 100644
--- a/src/g_doom/a_doommisc.cpp
+++ b/src/g_doom/a_doommisc.cpp
@@ -22,7 +22,6 @@
 #include "vm.h"
 
 // Include all the other Doom stuff here to reduce compile time
-#include "a_arachnotron.cpp"
 #include "a_archvile.cpp"
 #include "a_bossbrain.cpp"
 #include "a_bruiser.cpp"
diff --git a/src/scripting/vm/vmbuilder.cpp b/src/scripting/vm/vmbuilder.cpp
index b58de0ea4..1b7c4ce70 100644
--- a/src/scripting/vm/vmbuilder.cpp
+++ b/src/scripting/vm/vmbuilder.cpp
@@ -693,7 +693,7 @@ void FFunctionBuildList::Build()
 		FCompileContext ctx(item.Func, item.Func->SymbolName == NAME_None ? nullptr : item.Func->Variants[0].Proto, item.FromDecorate);
 
 		// Allocate registers for the function's arguments and create local variable nodes before starting to resolve it.
-		VMFunctionBuilder buildit(true);
+		VMFunctionBuilder buildit(!!(item.Func->Variants[0].Flags & VARF_Action));
 		for(unsigned i=0;i<item.Func->Variants[0].Proto->ArgumentTypes.Size();i++)
 		{
 			auto type = item.Func->Variants[0].Proto->ArgumentTypes[i];
diff --git a/src/scripting/zscript/zcc_compile.cpp b/src/scripting/zscript/zcc_compile.cpp
index 8389975ef..723e82c8d 100644
--- a/src/scripting/zscript/zcc_compile.cpp
+++ b/src/scripting/zscript/zcc_compile.cpp
@@ -2042,6 +2042,15 @@ void ZCCCompiler::InitFunctions()
 				sym->AddVariant(NewPrototype(rets, args), argflags, argnames, afd == nullptr? nullptr : *(afd->VMPointer), varflags);
 				c->Type()->Symbols.ReplaceSymbol(sym);
 
+				if (!(f->Flags & ZCC_Native))
+				{
+					auto code = ConvertAST(f->Body);
+					if (code != nullptr)
+					{
+						sym->Variants[0].Implementation = FunctionBuildList.AddFunction(sym, code, FStringf("%s.%s", c->Type()->TypeName.GetChars(), FName(f->Name).GetChars()), false);
+					}
+				}
+
 				// todo: Check inheritance.
 				// todo: Process function bodies.
 			}
diff --git a/wadsrc/static/zscript/doom/arachnotron.txt b/wadsrc/static/zscript/doom/arachnotron.txt
index e3aa17d48..0e093323b 100644
--- a/wadsrc/static/zscript/doom/arachnotron.txt
+++ b/wadsrc/static/zscript/doom/arachnotron.txt
@@ -88,4 +88,27 @@ class ArachnotronPlasma : Actor
 	}
 }
 
+//===========================================================================
+//
+// Code (must be attached to Actor)
+//
+//===========================================================================
+
+extend class Actor
+{
+	void A_BspiAttack()
+	{
+		if (target)
+		{
+			A_FaceTarget();
+			P_SpawnMissile(target, "ArachnotronPlasma");
+		}
+	}
+	
+	void A_BabyMetal()
+	{
+		A_PlaySound("baby/walk", CHAN_BODY, 1, false, ATTN_IDLE);
+		A_Chase();
+	}
+}