diff --git a/scripts/circular.fe b/scripts/circular.fe
new file mode 100644
index 0000000..1c0ef6e
--- /dev/null
+++ b/scripts/circular.fe
@@ -0,0 +1,4 @@
+(= items (list 1 2 3 4))
+(setcar (cdr items) (cons items (cons 5 items)))
+(setcdr (cdr (cdr (cdr items))) items)
+(print items)
diff --git a/src/fe.c b/src/fe.c
index b4a1634..cd012ce 100644
--- a/src/fe.c
+++ b/src/fe.c
@@ -343,7 +343,7 @@ static void writestr(fe_Context *ctx, fe_WriteFn fn, void *udata, const char *s)
   while (*s) { fn(ctx, udata, *s++); }
 }
 
-void fe_write(fe_Context *ctx, fe_Object *obj, fe_WriteFn fn, void *udata, int qt) {
+static void write_(fe_Context *ctx, fe_Object *obj, fe_WriteFn fn, void *udata, int qt) {
   char buf[32];
 
   switch (type(obj)) {
@@ -357,22 +357,28 @@ void fe_write(fe_Context *ctx, fe_Object *obj, fe_WriteFn fn, void *udata, int q
       break;
 
     case FE_TPAIR:
+      if (tag(obj) & GCMARKBIT) { writestr(ctx, fn, udata, "..."); break; }
       fn(ctx, udata, '(');
       for (;;) {
-        fe_write(ctx, car(obj), fn, udata, 1);
+        /* mark 'obj' and write car(obj) */
+        fe_Object *tmp = car(obj);
+        tag(obj) |= GCMARKBIT;
+        write_(ctx, tmp, fn, udata, 1);
+        /* write cdr(obj) if isn't circular list */
         obj = cdr(obj);
         if (type(obj) != FE_TPAIR) { break; }
         fn(ctx, udata, ' ');
+        if (tag(obj) & GCMARKBIT) { writestr(ctx, fn, udata, "..."); break; }
       }
-      if (!isnil(obj)) {
+      if (!isnil(obj) && !(tag(obj) & GCMARKBIT)) {
         writestr(ctx, fn, udata, " . ");
-        fe_write(ctx, obj, fn, udata, 1);
+        write_(ctx, obj, fn, udata, 1);
       }
       fn(ctx, udata, ')');
       break;
 
     case FE_TSYMBOL:
-      fe_write(ctx, car(cdr(obj)), fn, udata, 0);
+      write_(ctx, car(cdr(obj)), fn, udata, 0);
       break;
 
     case FE_TSTRING:
@@ -395,6 +401,18 @@ void fe_write(fe_Context *ctx, fe_Object *obj, fe_WriteFn fn, void *udata, int q
   }
 }
 
+static void unmarkpairs(fe_Object *obj) {
+  for (; !isnil(obj) && (tag(obj) & GCMARKBIT); obj = cdr(obj)) {
+    tag(obj) &= ~GCMARKBIT;
+    unmarkpairs(car(obj));
+  }
+}
+
+void fe_write(fe_Context *ctx, fe_Object *obj, fe_WriteFn fn, void *udata, int qt) {
+  write_(ctx, obj, fn, udata, qt);
+  unmarkpairs(obj);
+}
+
 
 static void writefp(fe_Context *ctx, void *udata, char chr) {
   unused(ctx);