diff --git a/lua/cmp/config.lua b/lua/cmp/config.lua
index 80ff750..0a78227 100644
--- a/lua/cmp/config.lua
+++ b/lua/cmp/config.lua
@@ -26,9 +26,9 @@ end
 ---@param c cmp.ConfigSchema
 ---@param bufnr number|nil
 config.set_buffer = function(c, bufnr)
+  local revision = (config.buffers[bufnr] or {}).revision or 1
   config.buffers[bufnr] = c
-  config.buffers[bufnr].revision = config.buffers[bufnr].revision or 1
-  config.buffers[bufnr].revision = config.buffers[bufnr].revision + 1
+  config.buffers[bufnr].revision = revision + 1
 end
 
 ---@return cmp.ConfigSchema
diff --git a/lua/cmp/core.lua b/lua/cmp/core.lua
index 14c8db5..9b2deb0 100644
--- a/lua/cmp/core.lua
+++ b/lua/cmp/core.lua
@@ -48,10 +48,17 @@ end
 core.get_context = function(option)
   local prev = core.context:clone()
   prev.prev_context = nil
-  core.context = context.new(prev, option)
+  local ctx = context.new(prev, option)
+  core.set_context(ctx)
   return core.context
 end
 
+---Set new context
+---@param ctx cmp.Context
+core.set_context = function(ctx)
+  core.context = ctx
+end
+
 ---Get sources that sorted by priority
 ---@param statuses cmp.SourceStatus[]
 ---@return cmp.Source[]
@@ -149,6 +156,8 @@ end
 ---Invoke completion
 ---@param ctx cmp.Context
 core.complete = function(ctx)
+  core.set_context(ctx)
+
   local callback = function()
     local new = context.new(ctx)
     if new:changed(new.prev_context) then