diff --git a/collects/scheme/foreign.ss b/collects/scheme/foreign.ss
index 49574f088e..66e3d94127 100644
--- a/collects/scheme/foreign.ss
+++ b/collects/scheme/foreign.ss
@@ -1280,8 +1280,8 @@
        [(pointer) _pointer]
        [(gcpointer) _gcpointer]
        [(fpointer) _fpointer])
-     (lambda (v) (and v (cast _pointer v)))
-     (lambda (v) (and v (cast ctype v))))))
+     (lambda (v) (and v (cast v _pointer _pointer)))
+     (lambda (v) (and v (cast v _pointer ctype))))))
 
 (define* (_gcable ctype)
   (unless (memq (ctype-coretype ctype) '(pointer gcpointer))
@@ -1298,7 +1298,7 @@
   (let loop ([c (ctype-basetype c)])
     (if (symbol? c)
         c
-        (loop c))))
+        (loop (ctype-basetype c)))))
 
 ;; A macro version of the above two functions, using the defined name for a tag
 ;; string, and defining a predicate too.  The name should look like `_foo', the
diff --git a/src/foreign/foreign.c b/src/foreign/foreign.c
index f3360898fc..8e3f16a838 100644
--- a/src/foreign/foreign.c
+++ b/src/foreign/foreign.c
@@ -1629,7 +1629,13 @@ static void* SCHEME2C(Scheme_Object *type, void *dst, long delta,
         tmp = (void*)(SCHEME_FFIANYPTR_VAL(val));
         toff = SCHEME_FFIANYPTR_OFFSET(val);
         if (_offset) *_offset = toff;
-        (((void**)W_OFFSET(dst,delta))[0]) = tmp; return NULL;
+        if (basetype_p == NULL || (tmp == NULL && toff == 0)) {
+          (((void**)W_OFFSET(dst,delta))[0]) = (_offset ? tmp : (void*)W_OFFSET(tmp, toff));
+          return NULL;
+        } else {
+          *basetype_p = FOREIGN_gcpointer;
+          return _offset ? tmp : (void*)W_OFFSET(tmp, toff);
+        }
       } else {
         scheme_wrong_type("Scheme->C","gcpointer",0,1,&(val));
         return NULL; /* hush the compiler */
@@ -1644,7 +1650,13 @@ static void* SCHEME2C(Scheme_Object *type, void *dst, long delta,
       if (1) {
         Scheme_Object* tmp;
         tmp = (Scheme_Object*)(val);
-        (((Scheme_Object**)W_OFFSET(dst,delta))[0]) = tmp; return NULL;
+        if (basetype_p == NULL || tmp == NULL) {
+          (((Scheme_Object**)W_OFFSET(dst,delta))[0]) = tmp;
+          return NULL;
+        } else {
+          *basetype_p = FOREIGN_scheme;
+          return tmp;
+        }
       } else {
         scheme_wrong_type("Scheme->C","scheme",0,1,&(val));
         return NULL; /* hush the compiler */
diff --git a/src/foreign/foreign.ssc b/src/foreign/foreign.ssc
index c02d6999c0..295a0f0606 100755
--- a/src/foreign/foreign.ssc
+++ b/src/foreign/foreign.ssc
@@ -538,7 +538,8 @@ Scheme_Object *utf16_pointer_to_ucs4_string(unsigned short *utf)
                               [s->c  (get 's->c)]
                               [c->s  (get 'c->s)]
                               [offset (get 'offset)]
-                              [ptr?  (equal? "pointer" ftype)])
+                              [ptr? (or (equal? "pointer" ftype)
+                                        (equal? "gcpointer" ftype))])
                          body ...))
                      types)))]))