diff --git a/builtin/common/misc_helpers.lua b/builtin/common/misc_helpers.lua
index 1a3c586a72..0394ee56fd 100644
--- a/builtin/common/misc_helpers.lua
+++ b/builtin/common/misc_helpers.lua
@@ -119,6 +119,7 @@ end
 -- }]]
 function dump(value, indent)
 	indent = indent or "\t"
+	assert(type(indent) == "string", "dump()'s second argument should be a string or nil, to dump multiple things use dump({a, b}).")
 	local newline = indent == "" and "" or "\n"
 
 	local rope = {}