diff --git a/src/common/iso639.cpp b/src/common/iso639.cpp
index e053fdeb1..cffb704d5 100644
--- a/src/common/iso639.cpp
+++ b/src/common/iso639.cpp
@@ -560,17 +560,6 @@ map_iso639_2_to_iso639_1(std::string const &iso639_2_code) {
   return (lang != g_iso639_languages.end()) ? lang->iso639_1_code : empty_string;
 }
 
-bool
-is_popular_language(std::string const &language) {
-  static std::vector<std::string> s_popular_languages = { "Chinese", "Dutch", "English", "Finnish", "French", "German", "Italian", "Japanese", "Norwegian", "Portuguese", "Russian", "Spanish", "Spanish; Castilian", "Swedish" };
-  return brng::find(s_popular_languages, language) != s_popular_languages.end();
-}
-
-bool
-is_popular_language_code(std::string const &code) {
-  return brng::find(g_popular_language_codes, code) != g_popular_language_codes.end();
-}
-
 /** \brief Map a string to a ISO 639-2 language code
 
    Searches the array of ISO 639 codes. If \c s is a valid ISO 639-2
diff --git a/src/common/iso639.h b/src/common/iso639.h
index b0042c667..4a592e660 100644
--- a/src/common/iso639.h
+++ b/src/common/iso639.h
@@ -26,5 +26,3 @@ int map_to_iso639_2_code(std::string const &s, bool allow_short_english_names =
 bool is_valid_iso639_2_code(std::string const &s);
 std::string const &map_iso639_2_to_iso639_1(std::string const &iso639_2_code);
 void list_iso639_languages();
-bool is_popular_language(std::string const &lang);
-bool is_popular_language_code(std::string const &code);