diff --git a/pkg/argus_wasm_bg.wasm b/pkg/argus_wasm_bg.wasm
index 0d9d2d9..87d21e0 100644
Binary files a/pkg/argus_wasm_bg.wasm and b/pkg/argus_wasm_bg.wasm differ
diff --git a/src/lib.rs b/src/lib.rs
index a8dabe6..7d7b176 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -86,16 +86,18 @@ pub fn eval_boolean(s: &str, js_trace: JsValue) -> JsValue {
         _ => return JsValue::from_str("expected boolean expression (this should never happen)"),
     };
     let mut result = Vec::<StateBuddyEvalResultEntry>::new();
-    if let Ok(r) = eval_result {
-        r.iter().for_each(|(timestamp, satisfied), | {
-            result.push(StateBuddyEvalResultEntry{
-                timestamp: timestamp.as_millis() as f64,
-                satisfied: *satisfied,
+    match eval_result {
+        Ok(r) => {
+            r.iter().for_each(|(timestamp, satisfied), | {
+                result.push(StateBuddyEvalResultEntry{
+                    timestamp: timestamp.as_millis() as f64,
+                    satisfied: *satisfied,
+                });
             });
-        });
-    }
-    else {
-        return JsValue::from_str("failed to evaluate expression");
+        }
+        Err(e) => {
+            return JsValue::from_str(format!("failed to evaluate expression: {}", e).as_str());
+        }
     }
     to_value(&StateBuddyEvalResult { entries: result }).expect("fuuuck")
 }