diff --git a/hxsl/Ast.hx b/hxsl/Ast.hx
index 6b73fbcc62..d77f49dca2 100644
--- a/hxsl/Ast.hx
+++ b/hxsl/Ast.hx
@@ -291,6 +291,7 @@ enum TGlobal {
 	InstanceID;
 	// gl globals
 	FragCoord;
+	FragDepth;
 	FrontFacing;
 	// bit casting
 	FloatBitsToInt;
@@ -522,6 +523,8 @@ class Tools {
 			return hasSideEffect(it) || hasSideEffect(loop);
 		case TArray(e, index):
 			return hasSideEffect(e) || hasSideEffect(index);
+		case TGlobal(FragDepth):
+			return true;
 		case TConst(_), TVar(_), TGlobal(_):
 			return false;
 		case TCall({ e : TGlobal(SetLayout) },_):
diff --git a/hxsl/Checker.hx b/hxsl/Checker.hx
index d55d5f9a22..9bd9c2b8db 100644
--- a/hxsl/Checker.hx
+++ b/hxsl/Checker.hx
@@ -186,7 +186,7 @@ class Checker {
 				];
 			case ImageStore:
 				[];
-			case VertexID, InstanceID, FragCoord, FrontFacing:
+			case VertexID, InstanceID, FragCoord, FrontFacing,FragDepth:
 				null;
 			case AtomicAdd:
 				[{ args : [{ name : "buf", type : TBuffer(TInt, SConst(0), RW) },{ name : "index", type : TInt }, { name : "data", type : TInt }], ret : TInt }];
@@ -225,6 +225,7 @@ class Checker {
 		globals.set("vertexID", { t : TInt, g : VertexID });
 		globals.set("instanceID", { t : TInt, g : InstanceID });
 		globals.set("fragCoord", { t : vec4, g : FragCoord });
+		globals.set("fragDepth", { t : TFloat, g : FragDepth });
 		globals.set("frontFacing", { t : TBool, g : FrontFacing });
 		for( gname => vl in gvars )
 			globals.set(gname, { t : TStruct([
@@ -418,6 +419,8 @@ class Checker {
 		case TArray(e, _):
 			checkWrite(e);
 			return;
+		case TGlobal(FragDepth):
+			return;
 		default:
 		}
 		error("This expression cannot be assigned", e.p);
diff --git a/hxsl/Dce.hx b/hxsl/Dce.hx
index 3e85dbd989..382e81d6c0 100644
--- a/hxsl/Dce.hx
+++ b/hxsl/Dce.hx
@@ -62,6 +62,7 @@ class Dce {
 	var used : Map<Int,VarDeps>;
 	var channelVars : Array<TVar>;
 	var markAsKeep : Bool;
+	var fragDepthId = Tools.allocVarId();
 
 	public function new() {
 	}
@@ -202,6 +203,27 @@ class Dce {
 			link(v, writeTo);
 		case TSwiz({ e : TVar(v) }, swiz):
 			link(v, writeTo, swizBits(swiz));
+		case TBinop(op, { e : TGlobal(FragDepth) }, e2 ):
+			var v:TVar = {
+				id: fragDepthId,
+				name: "FragDepth",
+				type: TFloat,
+				kind: Global,
+			};
+			var v = get(v);
+			switch(op) {
+				// Last assign will always clear all other dependencies
+				case OpAssign:
+					v.adeps = [];
+					v.deps.clear();
+				case OpAssignOp(_):
+				default:
+					return;
+			}
+			v.keep = 15;
+			writeTo.push(v, 15);
+			check(e2, writeTo, isAffected);
+			writeTo.pop();
 		case TBinop(OpAssign | OpAssignOp(_), { e : TVar(v) }, e):
 			var v = get(v);
 			writeTo.push(v,15);
@@ -296,6 +318,8 @@ class Dce {
 				count++;
 			}
 			return { e : TBlock(out), p : e.p, t : e.t };
+		case TBinop(OpAssign | OpAssignOp(_), {e: TGlobal(FragDepth) },{e: TVar(v) }) if(get(v).used == 0):
+			return { e : TConst(CNull), t : e.t, p : e.p }; 
 		case TVarDecl(v,_) | TBinop(OpAssign | OpAssignOp(_), { e : (TVar(v) | TSwiz( { e : TVar(v) }, _) | TArray( { e : TVar(v) }, _)) }, _) if( get(v).used == 0 ):
 			return { e : TConst(CNull), t : e.t, p : e.p };
 		case TBinop(OpAssign | OpAssignOp(_), { e : TSwiz( { e : TVar(v) }, swiz) }, _) if( get(v).used & swizBits(swiz) == 0 ):
diff --git a/hxsl/GlslOut.hx b/hxsl/GlslOut.hx
index daf30e09f5..a2cf628d93 100644
--- a/hxsl/GlslOut.hx
+++ b/hxsl/GlslOut.hx
@@ -67,6 +67,7 @@ class GlslOut {
 		set(BVec3, "bvec3");
 		set(BVec4, "bvec4");
 		set(FragCoord, "gl_FragCoord");
+		set(FragDepth, "gl_FragDepth");
 		set(FrontFacing, "gl_FrontFacing");
 		set(FloatBitsToUint, "_floatBitsToUint");
 		set(UintBitsToFloat, "_uintBitsToFloat");
diff --git a/hxsl/Linker.hx b/hxsl/Linker.hx
index b16c608f66..92e700a2aa 100644
--- a/hxsl/Linker.hx
+++ b/hxsl/Linker.hx
@@ -31,6 +31,7 @@ private class ShaderInfos {
 	public var vertex : Null<Bool>;
 	public var onStack : Bool;
 	public var hasDiscard : Bool;
+	public var hasFragDepth : Bool;
 	public var isCompute : Bool;
 	public var marked : Null<Bool>;
 	public function new(n, v) {
@@ -201,6 +202,23 @@ class Linker {
 			return { e : TVar(v.v), t : v.v.type, p : e.p };
 		case TBinop(op, e1, e2):
 			switch( [op, e1.e] ) {
+			case [OpAssign | OpAssignOp(_), TGlobal(FragDepth)]:
+				if( curShader != null ) {
+					curShader.hasFragDepth = true;
+				}
+				
+				var e2 = mapExprVar(e2);
+				switch(e2.e) {
+					case TVar(v2):
+						var v2 = allocVar(v2,e2.p);
+						if( !curShader.readMap.exists(v2.id) ) {
+							curShader.readMap.set(v2.id, v2);
+							curShader.readVars.push(v2);
+						}
+					default:
+				}
+
+				return { e : TBinop(op, { e : TGlobal(FragDepth),t : TFloat, p : e.p }, e2), t : e.t, p : e.p };
 			case [OpAssign, TVar(v)] if( !locals.exists(v.id) ):
 				var e2 = mapExprVar(e2);
 				var v = allocVar(v, e1.p);
@@ -414,7 +432,7 @@ class Linker {
 
 		// force shaders containing discard to be included
 		for( s in shaders )
-			if( s.hasDiscard || s.isCompute ) {
+			if( s.hasDiscard || s.isCompute || s.hasFragDepth) {
 				initDependencies(s);
 				entry.deps.set(s, true);
 			}