diff --git a/doc/ref/create.xml b/doc/ref/create.xml
index 33dd9d62e6..62e44a455f 100644
--- a/doc/ref/create.xml
+++ b/doc/ref/create.xml
@@ -47,8 +47,8 @@ and why it is useful to have a declaration part and an implementation part.
 
 <Description>
 New objects are created by <Ref Func="Objectify"/>.
-<A>data</A> is a list or a record, and <A>type</A> is the type that the
-desired object shall have.
+<A>data</A> must be a plain list or a plain record, and <A>type</A>
+is the type that the desired object shall have.
 <Ref Func="Objectify"/> turns <A>data</A> into an object with type
 <A>type</A>.
 That is, <A>data</A> is changed, and afterwards it will not be a list or a
diff --git a/lib/type1.g b/lib/type1.g
index 329e23c61c..9ea3efdb77 100644
--- a/lib/type1.g
+++ b/lib/type1.g
@@ -727,8 +727,8 @@ end );
 ##  will take a lot of time for type changes.
 ##  You can avoid this  by  setting the attributes immediately while the
 ##  object is created, as follows.
-##  <Ref Func="ObjectifyWithAttributes"/>
-##  changes the type of object <A>obj</A> to type <A>type</A>
+##  <Ref Func="ObjectifyWithAttributes"/> takes a plain list or record
+##  <A>obj</A> and turns it an object just like <Ref Func="Objectify"/>
 ##  and sets attribute <A>attr1</A> to <A>val1</A>,
 ##  sets attribute <A>attr2</A> to <A>val2</A> and so forth.
 ##  <P/>
diff --git a/src/objects.c b/src/objects.c
index 70ecd1a329..911ac30685 100644
--- a/src/objects.c
+++ b/src/objects.c
@@ -228,20 +228,17 @@ void SET_TYPE_OBJ(Obj obj, Obj type)
         break;
 
     default:
-        if (IS_STRING_REP(obj)) {
-            // FIXME/TODO: Hap calls Objectify on a string...
+        if (!IS_PLIST(obj)) {
+            ErrorMayQuit("cannot change type of a %s", (Int)TNAM_OBJ(obj), 0);
         }
-        else if (IS_PLIST(obj)) {
+        // TODO: we should also reject immutable plists, but that risks
+        // breaking existing code
 #ifdef HPCGAP
-            MEMBAR_WRITE();
+        MEMBAR_WRITE();
 #endif
-            RetypeBag(obj, T_POSOBJ);
-            SET_TYPE_POSOBJ(obj, type);
-            CHANGED_BAG(obj);
-        }
-        else {
-            ErrorMayQuit("cannot change type of a %s", (Int)TNAM_OBJ(obj), 0);
-        }
+        RetypeBag(obj, T_POSOBJ);
+        SET_TYPE_POSOBJ(obj, type);
+        CHANGED_BAG(obj);
         break;
     }
 }
@@ -1338,10 +1335,7 @@ static Obj FuncSET_TYPE_POSOBJ(Obj self, Obj obj, Obj type)
     case T_POSOBJ:
         break;
     default:
-        if (IS_STRING_REP(obj)) {
-            // FIXME/TODO: Hap calls Objectify on a string...
-        }
-        else if (!IS_PLIST(obj)) {
+        if (!IS_PLIST(obj)) {
             ErrorMayQuit("You can't make a positional object from a %s",
                          (Int)TNAM_OBJ(obj), 0);
         }