autoload/lsp/completion.vim | 37 +++++++++++++++++++++----------------
 doc/lsp.txt                 |  6 ++++--

diff --git a/autoload/lsp/completion.vim b/autoload/lsp/completion.vim
index 607d78d52e69fdcfc3155f3daa3330f05cd24357..83885862d84072c1d2c5256bd7c60e3f790214c2 100644
--- a/autoload/lsp/completion.vim
+++ b/autoload/lsp/completion.vim
@@ -137,6 +137,26 @@     })
   endfor
 enddef
 
+# add completion from current buf
+def CompletionFromBuffer(items: list<dict<any>>)
+    var words = {}
+    for line in getline(1, '$')
+        for word in line->split('\W\+')
+            if !has_key(words, word) && len(word) > 1
+                words[word] = 1
+                items->add({
+                    label: word,
+                    data: {
+                        entryNames: [word],
+                    },
+                    kind: 26,
+                    documentation: "",
+                })
+            endif
+        endfor
+    endfor
+enddef
+
 # process the 'textDocument/completion' reply from the LSP server
 # Result: CompletionItem[] | CompletionList | null
 export def CompletionReply(lspserver: dict<any>, cItems: any)
@@ -173,22 +193,7 @@     CompletionUltiSnips(prefix, items)
   endif
 
   if opt.lspOptions.useBufferCompletion
-      # add completion from current buf
-      var words = {}
-      var text = join(getline(1, '$'), "\n")
-      for word in split(text, '\W\+')
-          if !has_key(words, word) && len(word) > 1
-              words[word] = 1
-              items->add({
-                  label: word,
-                  data: {
-                      entryNames: [word],
-                  },
-                  kind: 26,
-                  documentation: "",
-              })
-          endif
-      endfor
+    CompletionFromBuffer(items)
   endif
 
   var completeItems: list<dict<any>> = []
diff --git a/doc/lsp.txt b/doc/lsp.txt
index ef60be1226c974b53e1fb20e442de7826826bb9a..7ce342a0a60210b4d96c845355ef86b8681d0a7a 100644
--- a/doc/lsp.txt
+++ b/doc/lsp.txt
@@ -499,8 +499,10 @@ 			command to display the code action for the current
 			line, use a popup menu instead of echoing.
 			By default this is set to false.
 						*lsp-opt-useBufferCompletion*
-useBufferCompletion     |Boolean| option. If enable adds current buffer words
-			to autocompletion list. Мay degrade vim performance.
+useBufferCompletion     |Boolean| option. If enabled, the words from the current
+			buffer are added to the auto completion list. This may degrade Vim performance
+			as the current buffer contents are processed every time the completion
+			menu is displayed.
 			By default this is set to false.
 
 For example, to disable the automatic placement of signs for the LSP