diff --git a/ChangeLog b/ChangeLog
index 86840ab4ba..c22071f860 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Mar 17 21:24:52 2016  Yusuke Endoh  <mame@ruby-lang.org>
+
+	* array.c (rb_ary_max, rb_ary_min): implement a block by itself instead
+	  of delegating Enumerable#max/min.
+
 Thu Mar 17 21:09:34 2016  Yusuke Endoh  <mame@ruby-lang.org>
 
 	* array.c (rb_ary_max, rb_ary_min): Array#max and Array#min added.
diff --git a/array.c b/array.c
index f59b4b9e2e..75dbcd4184 100644
--- a/array.c
+++ b/array.c
@@ -4210,14 +4210,24 @@ rb_ary_max(int argc, VALUE *argv, VALUE ary)
 
     rb_scan_args(argc, argv, "01", &num);
 
-    if (!NIL_P(num) || rb_block_given_p())
+    if (!NIL_P(num))
        return rb_call_super(argc, argv); /* XXX: should redefine? */
 
-    for (i = 0; i < RARRAY_LEN(ary); i++) {
-       v = RARRAY_AREF(ary, i);
-       if (result == Qundef || OPTIMIZED_CMP(v, result, cmp_opt) > 0) {
-           result = v;
-       }
+    if (rb_block_given_p()) {
+	for (i = 0; i < RARRAY_LEN(ary); i++) {
+	   v = RARRAY_AREF(ary, i);
+	   if (result == Qundef || rb_cmpint(rb_yield_values(2, v, result), v, result) > 0) {
+	       result = v;
+	   }
+	}
+    }
+    else {
+	for (i = 0; i < RARRAY_LEN(ary); i++) {
+	   v = RARRAY_AREF(ary, i);
+	   if (result == Qundef || OPTIMIZED_CMP(v, result, cmp_opt) > 0) {
+	       result = v;
+	   }
+	}
     }
     if (result == Qundef) return Qnil;
     return result;
@@ -4255,14 +4265,24 @@ rb_ary_min(int argc, VALUE *argv, VALUE ary)
 
     rb_scan_args(argc, argv, "01", &num);
 
-    if (!NIL_P(num) || rb_block_given_p())
+    if (!NIL_P(num))
        return rb_call_super(argc, argv); /* XXX: should redefine? */
 
-    for (i = 0; i < RARRAY_LEN(ary); i++) {
-       v = RARRAY_AREF(ary, i);
-       if (result == Qundef || OPTIMIZED_CMP(v, result, cmp_opt) < 0) {
-           result = v;
-       }
+    if (rb_block_given_p()) {
+	for (i = 0; i < RARRAY_LEN(ary); i++) {
+	   v = RARRAY_AREF(ary, i);
+	   if (result == Qundef || rb_cmpint(rb_yield_values(2, v, result), v, result) < 0) {
+	       result = v;
+	   }
+	}
+    }
+    else {
+	for (i = 0; i < RARRAY_LEN(ary); i++) {
+	   v = RARRAY_AREF(ary, i);
+	   if (result == Qundef || OPTIMIZED_CMP(v, result, cmp_opt) < 0) {
+	       result = v;
+	   }
+	}
     }
     if (result == Qundef) return Qnil;
     return result;