diff --git a/moo/bin/main.c b/moo/bin/main.c
index 52cf176..230f7a6 100644
--- a/moo/bin/main.c
+++ b/moo/bin/main.c
@@ -291,7 +291,11 @@ int main (int argc, char* argv[])
 		}
 	}
 
-/*MOO_DEBUG2 (moo, "XXXXXXXXXXXXXXXXXXXXX %O %ld\n", moo_ooitoint(moo, MOO_TYPE_MIN(moo_ooi_t)), MOO_TYPE_MIN(moo_ooi_t));*/
+/*MOO_DEBUG2 (moo, "XXXXXXXXXXXXXXXXXXXXX %O %zd\n", moo_ooitoint(moo, MOO_TYPE_MIN(moo_ooi_t)), MOO_TYPE_MIN(moo_ooi_t));
+MOO_DEBUG2 (moo, "XXXXXXXXXXXXXXXXXXXXX %O %jd\n", moo_intmaxtoint(moo, MOO_TYPE_MIN(moo_intmax_t)), MOO_TYPE_MIN(moo_intmax_t));
+MOO_DEBUG2 (moo, "XXXXXXXXXXXXXXXXXXXXX %O %ju\n", moo_uintmaxtoint(moo, MOO_TYPE_MAX(moo_uintmax_t)), MOO_TYPE_MAX(moo_uintmax_t));
+MOO_DEBUG2 (moo, "XXXXXXXXXXXXXXXXXXXXX %O %zu\n", moo_oowtoint(moo, MOO_TYPE_MAX(moo_oow_t)), MOO_TYPE_MAX(moo_oow_t));*/
+
 	MOO_DEBUG0 (moo, "COMPILE OK. STARTING EXECUTION...\n");
 	xret = 0;
 
diff --git a/moo/lib/bigint.c b/moo/lib/bigint.c
index 3a177b5..0428f90 100644
--- a/moo/lib/bigint.c
+++ b/moo/lib/bigint.c
@@ -625,13 +625,19 @@ static MOO_INLINE moo_oop_t make_bigint_with_intmax (moo_t* moo, moo_intmax_t v)
 	moo_oow_t len;
 	moo_liw_t buf[MOO_SIZEOF_INTMAX_T / MOO_SIZEOF_LIW_T];
 	moo_uintmax_t ui;
+	moo_oop_class_t _class;
 
-/*TODO: enhance to support MOO_TYPE_MIN(moo_intmax_t) */
-	/* this is not a generic function. it can't handle v 
-	 * if it's MOO_TYPE_MIN(moo_intmax_t) */
-	MOO_ASSERT (moo, v > MOO_TYPE_MIN(moo_intmax_t));
+	if (v >= 0)
+	{
+		ui = v;
+		_class = moo->_large_positive_integer;
+	}
+	else
+	{
+		ui = (v == MOO_TYPE_MIN(moo_intmax_t))? ((moo_uintmax_t)MOO_TYPE_MAX(moo_intmax_t) + 1): -v;
+		_class = moo->_large_negative_integer;
+	}
 
-	ui = (v >= 0)? v: -v;
 	len = 0;
 	do
 	{
@@ -640,7 +646,23 @@ static MOO_INLINE moo_oop_t make_bigint_with_intmax (moo_t* moo, moo_intmax_t v)
 	}
 	while (ui > 0);
 
-	return moo_instantiate(moo, ((v >= 0)? moo->_large_positive_integer: moo->_large_negative_integer), buf, len);
+	return moo_instantiate(moo, _class, buf, len);
+}
+
+static MOO_INLINE moo_oop_t make_bigint_with_uintmax (moo_t* moo, moo_uintmax_t ui)
+{
+	moo_oow_t len;
+	moo_liw_t buf[MOO_SIZEOF_INTMAX_T / MOO_SIZEOF_LIW_T];
+
+	len = 0;
+	do
+	{
+		buf[len++] = (moo_liw_t)ui;
+		ui = ui >> MOO_LIW_BITS;
+	}
+	while (ui > 0);
+
+	return moo_instantiate(moo, moo->_large_positive_integer, buf, len);
 }
 
 moo_oop_t moo_oowtoint (moo_t* moo, moo_oow_t w)
@@ -681,6 +703,18 @@ moo_oop_t moo_intmaxtoint (moo_t* moo, moo_intmax_t i)
 	}
 }
 
+moo_oop_t moo_uintmaxtoint (moo_t* moo, moo_uintmax_t i)
+{
+	if (MOO_IN_SMOOI_RANGE(i))
+	{
+		return MOO_SMOOI_TO_OOP(i);
+	}
+	else
+	{
+		return make_bigint_with_uintmax(moo, i);
+	}
+}
+
 static MOO_INLINE moo_oop_t expand_bigint (moo_t* moo, moo_oop_t oop, moo_oow_t inc)
 {
 	moo_oop_t z;
diff --git a/moo/lib/moo.h b/moo/lib/moo.h
index a79974e..9ed5587 100644
--- a/moo/lib/moo.h
+++ b/moo/lib/moo.h
@@ -2221,10 +2221,10 @@ MOO_EXPORT moo_oop_t moo_intmaxtoint (
 	moo_intmax_t i
 );
 
-/*MOO_EXPORT moo_oop_t moo_uintmaxtoint (
+MOO_EXPORT moo_oop_t moo_uintmaxtoint (
 	moo_t*        moo,
 	moo_uintmax_t i
-);*/
+);
 
 MOO_EXPORT int moo_inttouintmax (
 	moo_t*         moo,