diff --git a/lua/lualine/highlight.lua b/lua/lualine/highlight.lua
index 2f79601..8c31760 100644
--- a/lua/lualine/highlight.lua
+++ b/lua/lualine/highlight.lua
@@ -10,7 +10,22 @@ local function highlight (name, foreground, background, special)
   return table.concat(command, ' ')
 end
 
+local function apply_defaults_to_theme(theme)
+  local modes = {'insert', 'visual', 'replace', 'command', 'terminal', 'inactive'}
+  for _, mode in ipairs(modes) do
+    if not theme[mode] then
+      theme[mode] = theme['normal']
+    else
+      for section_name, section in pairs(theme['normal']) do
+        theme[mode][section_name] = (theme[mode][section_name] or section)
+      end
+    end
+  end
+  return theme
+end
+
 function M.create_highlight_groups(theme)
+  apply_defaults_to_theme(theme)
   for mode, sections in pairs(theme) do
     for section, colorscheme in pairs(sections) do
       local special = nil