diff --git a/api.lua b/api.lua
index 4a4f667..92b4670 100644
--- a/api.lua
+++ b/api.lua
@@ -312,8 +312,8 @@ local function create_question(id, question, category, sort, allowed_types,
 
     -- Specialcase : answers cannot be nil or empty if allowedtypes has either multiplechoice or singlechoice
     if (((answers == nil) or (next(answers) == nil)) and
-        ((allowed_types["multiplechoice"] ~= nil) or
-            (allowed_types["singlechoice"] ~= nil))) then
+        ((yl_survey.table_contains(allowed_types, "multiplechoice") == true) or
+            (yl_survey.table_contains(allowed_types, "singlechoice") == true))) then
         return false, yl_survey.t(
                    "answers cannot be nil or empty if allowedtypes has either multiplechoice or singlechoice")
     end
@@ -415,8 +415,8 @@ local function edit_question(id, q_id, question, sort, category, allowed_types,
 
     -- Specialcase : answers cannot be nil or empty if allowedtypes has either multiplechoice or singlechoice
     if ((answers ~= nil) and (next(answers) ~= nil) and
-        ((allowed_types["multiplechoice"] ~= nil) or
-            (allowed_types["singlechoice"] ~= nil))) then
+        ((yl_survey.table_contains(allowed_types, "multiplechoice") == true) or
+            (yl_survey.table_contains(allowed_types, "singlechoice") == true))) then
         return false, yl_survey.t(
                    "answers cannot be nil or empty if allowedtypes has either multiplechoice or singlechoice")
     end
@@ -446,9 +446,7 @@ local function edit_question(id, q_id, question, sort, category, allowed_types,
     local no = 0
     local n_responses = t_question["responses"] or {}
     if (delete_responses == true) then
-        for _,_ in pairs(n_responses) do
-            no = no + 1
-        end
+        for _, _ in pairs(n_responses) do no = no + 1 end
         n_responses = {}
     end
 
diff --git a/internal.lua b/internal.lua
index 4719d28..d28597c 100644
--- a/internal.lua
+++ b/internal.lua
@@ -30,6 +30,24 @@ end
 
 function yl_survey.priv_exists(priv) return priv_exists(priv) end
 
+-- table.contains
+
+local function table_contains(t, m)
+    if ((type(m) ~= "number") and (type(m) ~= "string") and (type(m) ~= "boolean")) then
+        return nil, yl_survey.t("member must be primitive")
+    end
+    for _, v in pairs(t) do
+        if (v == m) then
+            return true
+        end
+    end
+    return false
+end
+
+function yl_survey.table_contains(t, m)
+    return table_contains(t, m)
+end
+
 -- Hash name
 
 local function hash_name(name)