diff --git a/array.c b/array.c
index 1d536284d5..99942bc27b 100644
--- a/array.c
+++ b/array.c
@@ -4014,17 +4014,23 @@ rb_ary_includes(VALUE ary, VALUE item)
 }
 
 static VALUE
-rb_ary_includes_by_eql(VALUE ary, VALUE item)
+rb_ary_includes_by_hash(VALUE ary, VALUE item)
 {
     long i;
-    VALUE e;
+    VALUE e, item_hash, e_hash;
+
+    ID id_hash = rb_intern("hash");
+
+    item_hash = rb_funcall(item, id_hash, 0);
 
     for (i=0; i<RARRAY_LEN(ary); i++) {
-	e = RARRAY_AREF(ary, i);
-	if (rb_eql(item, e)) {
-	    return Qtrue;
-	}
+        e = RARRAY_AREF(ary, i);
+        e_hash = rb_funcall(e, id_hash, 0);
+        if (rb_eql(item_hash, e_hash)) {
+            return Qtrue;
+        }
     }
+
     return Qfalse;
 }
 
@@ -4184,7 +4190,7 @@ rb_ary_diff(VALUE ary1, VALUE ary2)
     if (RARRAY_LEN(ary1) <= SMALL_ARRAY_LEN || RARRAY_LEN(ary2) <= SMALL_ARRAY_LEN) {
 	for (i=0; i<RARRAY_LEN(ary1); i++) {
 	    VALUE elt = rb_ary_elt(ary1, i);
-	    if (rb_ary_includes_by_eql(ary2, elt)) continue;
+	    if (rb_ary_includes_by_hash(ary2, elt)) continue;
 	    rb_ary_push(ary3, elt);
 	}
 	return ary3;
@@ -4230,8 +4236,8 @@ rb_ary_and(VALUE ary1, VALUE ary2)
     if (RARRAY_LEN(ary1) <= SMALL_ARRAY_LEN && RARRAY_LEN(ary2) <= SMALL_ARRAY_LEN) {
 	for (i=0; i<RARRAY_LEN(ary1); i++) {
 	    v = RARRAY_AREF(ary1, i);
-	    if (!rb_ary_includes_by_eql(ary2, v)) continue;
-	    if (rb_ary_includes_by_eql(ary3, v)) continue;
+	    if (!rb_ary_includes_by_hash(ary2, v)) continue;
+	    if (rb_ary_includes_by_hash(ary3, v)) continue;
 	    rb_ary_push(ary3, v);
 	}
 	return ary3;
@@ -4286,12 +4292,12 @@ rb_ary_or(VALUE ary1, VALUE ary2)
 	ary3 = rb_ary_new();
 	for (i=0; i<RARRAY_LEN(ary1); i++) {
 	    VALUE elt = rb_ary_elt(ary1, i);
-	    if (rb_ary_includes_by_eql(ary3, elt)) continue;
+	    if (rb_ary_includes_by_hash(ary3, elt)) continue;
 	    rb_ary_push(ary3, elt);
 	}
 	for (i=0; i<RARRAY_LEN(ary2); i++) {
 	    VALUE elt = rb_ary_elt(ary2, i);
-	    if (rb_ary_includes_by_eql(ary3, elt)) continue;
+	    if (rb_ary_includes_by_hash(ary3, elt)) continue;
 	    rb_ary_push(ary3, elt);
 	}
 	return ary3;