diff --git a/lib/net/protocol.rb b/lib/net/protocol.rb
index f241681983..a48200f6b3 100644
--- a/lib/net/protocol.rb
+++ b/lib/net/protocol.rb
@@ -156,7 +156,7 @@ module Net # :nodoc:
       read_bytes = 0
       begin
         while read_bytes + rbuf_size < len
-          if s = rbuf_consume_all_shareable!
+          if s = rbuf_consume_all
             read_bytes += s.bytesize
             dest << s
           end
@@ -177,7 +177,7 @@ module Net # :nodoc:
       read_bytes = 0
       begin
         while true
-          if s = rbuf_consume_all_shareable!
+          if s = rbuf_consume_all
             read_bytes += s.bytesize
             dest << s
           end
@@ -249,18 +249,8 @@ module Net # :nodoc:
       @rbuf.bytesize - @rbuf_offset
     end
 
-    # Warning: this method may share the buffer to avoid
-    # copying. The caller must no longer use the returned
-    # string once rbuf_fill has been called again
-    def rbuf_consume_all_shareable!
-      @rbuf_empty = true
-      buf = if @rbuf_offset == 0
-        @rbuf
-      else
-        @rbuf.byteslice(@rbuf_offset..-1)
-      end
-      @rbuf_offset = @rbuf.bytesize
-      buf
+    def rbuf_consume_all
+      rbuf_consume if rbuf_size > 0
     end
 
     def rbuf_consume(len = nil)