diff --git a/errors.lua b/errors.lua
index 8dad2e2..2484649 100644
--- a/errors.lua
+++ b/errors.lua
@@ -86,10 +86,10 @@ local function correct_error (self, module_suffix, format_msg, gotten_string, po
     assert(type(module_suffix) == 'string')
     format_msg = format_msg or DEFAULT_ERROR_MSG_CORRECT
     lvl = lvl or 0
-    assert(type(format_msg)    == 'string')
-    assert(type(gotten_string) == 'string')
-    assert(type(possible_strings) == 'table')
-    assert(type(lvl) == 'number')
+    assert(type(format_msg)    == 'string', 'Internal errors error: incorrect type for argument format_msg')
+    assert(type(gotten_string) == 'string', 'Internal errors error: incorrect type for argument gotten_string')
+    assert(type(possible_strings) == 'table', 'Internal errors error: incorrect type for argument possible_strings')
+    assert(type(lvl) == 'number', 'Internal errors error: incorrect type for argument lvl')
 
     -- Do stuff
     possible_strings = string_dist.strings_with_highest_similarity(gotten_string, possible_strings)