diff --git a/kiss/src/kiss/KissInterp.hx b/kiss/src/kiss/KissInterp.hx
index a1aa863c..734f9652 100644
--- a/kiss/src/kiss/KissInterp.hx
+++ b/kiss/src/kiss/KissInterp.hx
@@ -1,5 +1,6 @@
 package kiss;
 
+import hscript.Parser;
 import hscript.Interp;
 import kiss.Prelude;
 
@@ -12,6 +13,7 @@ import kiss.Prelude;
  */
 class KissInterp extends Interp {
     var nullForUnknownVar:Bool;
+    var parser = new Parser();
 
     // TODO standardize this with KissConfig.prepareInterp
     public function new(nullForUnknownVar = false) {
@@ -30,6 +32,11 @@ class KissInterp extends Interp {
         variables.set("kiss", {});
     }
 
+    public function evalKiss(kissStr:String):Dynamic {
+        return execute(parser.parseString(Prelude.convertToHScript(kissStr)));
+    }
+
+    // In some contexts, undefined variables should just return "null" as a falsy value
     override function resolve(id:String):Dynamic {
         if (nullForUnknownVar) {
             return try {
diff --git a/projects/nat-archive-tool/src/nat/BoolExpInterp.hx b/projects/nat-archive-tool/src/nat/BoolExpInterp.hx
index 41f835da..10d0a236 100644
--- a/projects/nat-archive-tool/src/nat/BoolExpInterp.hx
+++ b/projects/nat-archive-tool/src/nat/BoolExpInterp.hx
@@ -1,7 +1,6 @@
 package nat;
 
 import kiss.KissInterp;
-import hscript.Parser;
 import kiss.Prelude;
 
 @:build(kiss.Kiss.build())
diff --git a/projects/nat-archive-tool/src/nat/BoolExpInterp.kiss b/projects/nat-archive-tool/src/nat/BoolExpInterp.kiss
index 2b2a05d2..9abb6a3b 100644
--- a/projects/nat-archive-tool/src/nat/BoolExpInterp.kiss
+++ b/projects/nat-archive-tool/src/nat/BoolExpInterp.kiss
@@ -1,9 +1,5 @@
 (function eval [:String expStr :Array<String> activeConditions]
-    (let [hscript (Prelude.convertToHScript expStr)
-            parser (new Parser)
-            hscriptExp (parser.parseString hscript)
-            interp (new BoolExpInterp)]
-
+    (let [interp (new BoolExpInterp)]
         (doFor condition activeConditions
             (interp.variables.set condition true))
-        ?(interp.execute hscriptExp)))
+        ?(interp.evalKiss expStr)))