diff --git a/mihxil-theories/src/main/java/org/meeuw/theories/BasicObjectTheory.java b/mihxil-theories/src/main/java/org/meeuw/theories/BasicObjectTheory.java
index 78b1a8bf..872d37a5 100644
--- a/mihxil-theories/src/main/java/org/meeuw/theories/BasicObjectTheory.java
+++ b/mihxil-theories/src/main/java/org/meeuw/theories/BasicObjectTheory.java
@@ -143,7 +143,7 @@ default void toString(@ForAll(DATAPOINTS) E object) {
      * The implementation for equals datapoints (see {@link #equalDatapoints()}.
      * Defaults to {@link Objects#equals(Object, Object)}.
      */
-    default boolean equals(Object e1, Object e2) {
+    default boolean equals(E e1, E e2) {
         return Objects.equals(e1, e2);
     }