diff --git a/lua/wikis/commons/TeamTemplate.lua b/lua/wikis/commons/TeamTemplate.lua
index fea51c9a51b..4d340a4046e 100644
--- a/lua/wikis/commons/TeamTemplate.lua
+++ b/lua/wikis/commons/TeamTemplate.lua
@@ -83,11 +83,14 @@ end
 --[[
 Same as TeamTemplate.getRaw, except that it returns nil if the team template
 does not exist.
+
+Throws if `team` is `nil`.
 ]]
 ---@param team string
 ---@param date string|number?
 ---@return teamTemplateData?
 function TeamTemplate.getRawOrNil(team, date)
+	assert(team ~= nil, 'TeamTemplate.getRawOrNil: \'team\' must not be nil')
 	team = team:gsub('_', ' '):lower()
 
 	-- return mw.ext.TeamTemplate.raw(team, date)