diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 026aaad2..4b4265e3 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -9,12 +9,16 @@ on:
 
 jobs:
   build:
+    strategy:
+      matrix:
+        haxe-version: [latest, 4.3.7, 4.2.5]
+      fail-fast: false
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v3
-    - uses: krdlab/setup-haxe@v1
+    - uses: krdlab/setup-haxe@v2
       with:
-          haxe-version: 4.3.4
+        haxe-version: ${{ matrix.haxe-version }}
     - name: Install haxelib dependencies
       run: |
         haxelib install hx3compat
diff --git a/hscript/Checker.hx b/hscript/Checker.hx
index ab7c7abb..399a6708 100644
--- a/hscript/Checker.hx
+++ b/hscript/Checker.hx
@@ -1203,7 +1203,7 @@ class Checker {
 			switch( e.e ) {
 			case EField(obj, f):
 				if( cf.isMethod ) {
-					switch( callExpr?.e ) {
+					switch( callExpr == null ? null : callExpr.e ) {
 					case null:
 					case ECall(ec,params) if( ec == e ):
 						e.e = EField(acc,f);
@@ -1534,7 +1534,7 @@ class Checker {
 
 	function getTypeAccess( t : TType, expr : Expr, ?field : String ) : ExprDef {
 		var path = switch( t ) {
-		case TInst(c,_): c.runtimePath ?? c.name;
+		case TInst(c,_): c.runtimePath != null ? c.runtimePath : c.name;
 		case TEnum(e,_): e.name;
 		default: return null;
 		}
diff --git a/hscript/Interp.hx b/hscript/Interp.hx
index ce8cb58d..b2c959b0 100644
--- a/hscript/Interp.hx
+++ b/hscript/Interp.hx
@@ -56,11 +56,13 @@ class Interp {
 		variables.set("$resolve", resolveType);
 	}
 
+	#if js
+	static var ABS_CACHE = new Map();
+	#end
 	function resolveType( path : String ) : Dynamic {
 		#if js
 		// abstract type is not part of the class map
 		if( path.charCodeAt(0) == '#'.code ) {
-			static var ABS_CACHE = new Map();
 			var c = ABS_CACHE.get(path);
 			if( c != null ) return c;
 			c = js.Lib.eval(path.substr(1));
diff --git a/hscript/JsInterp.hx b/hscript/JsInterp.hx
index 9161c441..2f91a7d6 100644
--- a/hscript/JsInterp.hx
+++ b/hscript/JsInterp.hx
@@ -264,6 +264,7 @@ class JsInterp extends Interp {
 			default:
 				error(EInvalidOp(op));
 			}
+			return null;
 		case EUnop(op, prefix, e):
 			switch( op ) {
 			case "!":
@@ -300,6 +301,7 @@ class JsInterp extends Interp {
 			default:
 				error(EInvalidOp(op));
 			}
+			return null;
 		case ECall(e, params):
 			var args = [for( p in params ) exprValue(p)];
 			switch( Tools.expr(e) ) {
diff --git a/hscript/LiveClass.hx b/hscript/LiveClass.hx
index 11d04192..20b04397 100644
--- a/hscript/LiveClass.hx
+++ b/hscript/LiveClass.hx
@@ -25,7 +25,7 @@ class LiveClass {
 		if( api == null )
 			CONFIG = null;
 		else
-			CONFIG = { api : api, srcPath : srcPath ?? [".","src"] }
+			CONFIG = { api : api, srcPath : srcPath != null ? srcPath : [".","src"] }
 	}
 
 	static function hasRet( e : Expr ) : Bool {