diff --git a/core/src/main/java/org/nwapw/abacus/plugin/NumberImplementation.java b/core/src/main/java/org/nwapw/abacus/plugin/NumberImplementation.java
index 70e085e..ad5d1d1 100644
--- a/core/src/main/java/org/nwapw/abacus/plugin/NumberImplementation.java
+++ b/core/src/main/java/org/nwapw/abacus/plugin/NumberImplementation.java
@@ -14,7 +14,7 @@ public abstract class NumberImplementation {
     /**
      * The list of paths through which this implementation can be promoted.
      */
-    private Map<Class<? extends NumberInterface>, Function<NumberInterface, NumberInterface>> promotionPaths;
+    private Map<String, Function<NumberInterface, NumberInterface>> promotionPaths;
     /**
      * The implementation class for this implementation.
      */
@@ -41,7 +41,7 @@ public abstract class NumberImplementation {
      *
      * @return the map of documentation paths.
      */
-    public final Map<Class<? extends NumberInterface>, Function<NumberInterface, NumberInterface>> getPromotionPaths() {
+    public final Map<String, Function<NumberInterface, NumberInterface>> getPromotionPaths() {
         return promotionPaths;
     }