diff --git a/src/context/providers/espresso/providers.js b/src/context/providers/espresso/providers.js
index e0d215d..a945913 100644
--- a/src/context/providers/espresso/providers.js
+++ b/src/context/providers/espresso/providers.js
@@ -59,7 +59,7 @@ export class QEPWXContextProvider extends mix(ExecutableContextProvider).with(
         return material.Basis.uniqueElements.length;
     }
 
-    static NTYP_WITH_LABELS() {
+    get NTYP_WITH_LABELS() {
         return this.atomSymbolsWithLabels.length;
     }