diff --git a/src/string.c b/src/string.c
index de8a671ac..b29a298c1 100644
--- a/src/string.c
+++ b/src/string.c
@@ -2956,7 +2956,7 @@ str_bytesplice(mrb_state *mrb, mrb_value str, mrb_int idx1, mrb_int len1, mrb_va
   if (RSTRING_LEN(replace) <= idx2+len2) {
     len2 = RSTRING_LEN(replace) - idx2;
   }
-  if (len2 == 0) return replace;
+  if (len2 == 0) return str;
   mrb_str_modify(mrb, s);
   if (len1 >= len2) {
     memmove(RSTR_PTR(s)+idx1, RSTRING_PTR(replace)+idx2, len2);
@@ -2971,7 +2971,7 @@ str_bytesplice(mrb_state *mrb, mrb_value str, mrb_int idx1, mrb_int len1, mrb_va
     memmove(RSTR_PTR(s)+idx1+len2, RSTR_PTR(s)+idx1+len1, slen-(idx1+len1));
     memmove(RSTR_PTR(s)+idx1, RSTRING_PTR(replace)+idx2, len2);
   }
-  return replace;
+  return str;
 }
 
 /*
diff --git a/test/t/string.rb b/test/t/string.rb
index 892899346..caba51b7c 100644
--- a/test/t/string.rb
+++ b/test/t/string.rb
@@ -902,62 +902,50 @@ end
 assert('String#bytesplice') do
   # range, replace (len1=len2)
   a = "0123456789"
-  assert_equal "ab", a.bytesplice(1..2, "ab")
-  assert_equal "0ab3456789", a
+  assert_equal "0ab3456789", a.bytesplice(1..2, "ab")
 
   # range, replace (len1>len2)
   a = "0123456789"
-  assert_equal "ab", a.bytesplice(1..3, "ab")
-  assert_equal "0ab456789", a
+  assert_equal "0ab456789", a.bytesplice(1..3, "ab")
 
   # range, replace (len1<len2)
   a = "0123456789"
-  assert_equal "ab", a.bytesplice(1..1, "ab")
-  assert_equal "0ab23456789", a
+  assert_equal "0ab23456789", a.bytesplice(1..1, "ab")
 
   # idx, len, replace (len1=len2)
   a = "0123456789"
-  assert_equal "ab", a.bytesplice(1, 2, "ab")
-  assert_equal "0ab3456789", a
+  assert_equal "0ab3456789", a.bytesplice(1, 2, "ab")
 
   # idx, len, replace (len1>len2)
   a = "0123456789"
-  assert_equal "ab", a.bytesplice(1, 3, "ab")
-  assert_equal "0ab456789", a
+  assert_equal "0ab456789", a.bytesplice(1, 3, "ab")
 
   # idx, len, replace (len1<len2)
   a = "0123456789"
-  assert_equal "ab", a.bytesplice(1, 1, "ab")
-  assert_equal "0ab23456789", a
+  assert_equal "0ab23456789", a.bytesplice(1, 1, "ab")
 
   b = "abcdefg"
   # range, replace, range (len1=len2)
   a = "0123456789"
-  assert_equal b, a.bytesplice(1..2, b, 0..1)
-  assert_equal "0ab3456789", a
+  assert_equal "0ab3456789", a.bytesplice(1..2, b, 0..1)
 
   # range, replace, range (len1>len2)
   a = "0123456789"
-  assert_equal b, a.bytesplice(1..3, b, 1..2)
-  assert_equal "0bc456789", a
+  assert_equal "0bc456789", a.bytesplice(1..3, b, 1..2)
 
   # range, replace, range (len1<len2)
   a = "0123456789"
-  assert_equal b, a.bytesplice(1..1, b, 2..3)
-  assert_equal "0cd23456789", a
+  assert_equal "0cd23456789", a.bytesplice(1..1, b, 2..3)
 
   # idx, len, replace, idx, len (len1=len2)
   a = "0123456789"
-  assert_equal b, a.bytesplice(1, 2, b, 0, 2)
-  assert_equal "0ab3456789", a
+  assert_equal "0ab3456789", a.bytesplice(1, 2, b, 0, 2)
 
   # idx, len, replace, idx, len (len1>len2)
   a = "0123456789"
-  assert_equal b, a.bytesplice(1, 3, b, 1, 2)
-  assert_equal "0bc456789", a
+  assert_equal "0bc456789", a.bytesplice(1, 3, b, 1, 2)
 
   # idx, len, replace, idx, len (len1<len2)
   a = "0123456789"
-  assert_equal b, a.bytesplice(1, 1, b, 2, 2)
-  assert_equal "0cd23456789", a
+  assert_equal "0cd23456789", a.bytesplice(1, 1, b, 2, 2)
 end