diff --git a/src/interval/interval_def.h b/src/interval/interval_def.h
index 370a3373b..2e0d77e93 100644
--- a/src/interval/interval_def.h
+++ b/src/interval/interval_def.h
@@ -1600,12 +1600,14 @@ template<typename T> void interval<T>::acosh() {
     numeric_traits<T>::acosh(m_lower);
     if(upper_kind() == XN_NUMERAL) {
         numeric_traits<T>::set_rounding(true);
-        numeric_traits<T>::acosh(m_lower);
+        numeric_traits<T>::acosh(m_upper);
     }
     lean_assert(check_invariant());
     return;
 }
 template<typename T> void interval<T>::atanh() {
+    lean_assert(lower_kind() == XN_NUMERAL && m_lower >= -1.0);
+    lean_assert(upper_kind() == XN_NUMERAL && m_upper <= 1.0);
     if(lower_kind() == XN_NUMERAL) {
         numeric_traits<T>::set_rounding(true);
         m_lower = -m_lower;
diff --git a/src/tests/interval/double_interval.cpp b/src/tests/interval/double_interval.cpp
index abbd72125..c2c76cb7c 100644
--- a/src/tests/interval/double_interval.cpp
+++ b/src/tests/interval/double_interval.cpp
@@ -966,6 +966,68 @@ static void double_interval_trans() {
     check_uop(double, cot, ozero_ninf);
     check_uop(double, cot, czero_pinf);
     check_uop(double, cot, czero_ninf);
+
+    cout << "=====================" << endl;
+    check_uop(double, asinh, i1);
+    check_uop(double, asinh, i2);
+    check_uop(double, asinh, i3);
+    check_uop(double, asinh, i4);
+    check_uop(double, asinh, i5);
+    check_uop(double, asinh, i6);
+    check_uop(double, asinh, i7);
+    check_uop(double, asinh, i8);
+    check_uop(double, asinh, i9);
+    check_uop(double, asinh, i10);
+    check_uop(double, asinh, i11);
+    check_uop(double, asinh, i12);
+    check_uop(double, asinh, i13);
+    check_uop(double, asinh, i14);
+    check_uop(double, asinh, i15);
+    check_uop(double, asinh, oi1);
+    check_uop(double, asinh, oi2);
+    check_uop(double, asinh, oi3);
+    check_uop(double, asinh, oi4);
+    check_uop(double, asinh, oi5);
+    check_uop(double, asinh, oi6);
+    check_uop(double, asinh, oi7);
+    check_uop(double, asinh, oi8);
+    check_uop(double, asinh, oi9);
+    check_uop(double, asinh, oi10);
+    check_uop(double, asinh, oi11);
+    check_uop(double, asinh, oi12);
+    check_uop(double, asinh, oi13);
+    check_uop(double, asinh, oi14);
+    check_uop(double, asinh, oi15);
+    check_uop(double, asinh, inf);
+    check_uop(double, asinh, ozero_pinf);
+    check_uop(double, asinh, ozero_ninf);
+    check_uop(double, asinh, czero_pinf);
+    check_uop(double, asinh, czero_ninf);
+
+    cout << "=====================" << endl;
+    check_uop(double, acosh, i1);
+    check_uop(double, acosh, i2);
+    check_uop(double, acosh, i5);
+    check_uop(double, acosh, i7);
+    check_uop(double, acosh, i8);
+    check_uop(double, acosh, oi1);
+    check_uop(double, acosh, oi2);
+    check_uop(double, acosh, oi5);
+    check_uop(double, acosh, oi7);
+    check_uop(double, acosh, oi8);
+
+    cout << "=====================" << endl;
+    check_uop(double, atanh, i10);
+    check_uop(double, atanh, i11);
+    check_uop(double, atanh, i12);
+    check_uop(double, atanh, i13);
+    check_uop(double, atanh, i14);
+    check_uop(double, atanh, i15);
+    check_uop(double, atanh, oi11);
+    check_uop(double, atanh, oi12);
+    check_uop(double, atanh, oi13);
+    check_uop(double, atanh, oi14);
+    check_uop(double, atanh, oi15);
 }
 
 int main() {
diff --git a/src/tests/interval/float_interval.cpp b/src/tests/interval/float_interval.cpp
index 8bb0f3746..45705a7d1 100644
--- a/src/tests/interval/float_interval.cpp
+++ b/src/tests/interval/float_interval.cpp
@@ -966,6 +966,68 @@ static void float_interval_trans() {
     check_uop(float, cot, ozero_ninf);
     check_uop(float, cot, czero_pinf);
     check_uop(float, cot, czero_ninf);
+
+    cout << "=====================" << endl;
+    check_uop(float, asinh, i1);
+    check_uop(float, asinh, i2);
+    check_uop(float, asinh, i3);
+    check_uop(float, asinh, i4);
+    check_uop(float, asinh, i5);
+    check_uop(float, asinh, i6);
+    check_uop(float, asinh, i7);
+    check_uop(float, asinh, i8);
+    check_uop(float, asinh, i9);
+    check_uop(float, asinh, i10);
+    check_uop(float, asinh, i11);
+    check_uop(float, asinh, i12);
+    check_uop(float, asinh, i13);
+    check_uop(float, asinh, i14);
+    check_uop(float, asinh, i15);
+    check_uop(float, asinh, oi1);
+    check_uop(float, asinh, oi2);
+    check_uop(float, asinh, oi3);
+    check_uop(float, asinh, oi4);
+    check_uop(float, asinh, oi5);
+    check_uop(float, asinh, oi6);
+    check_uop(float, asinh, oi7);
+    check_uop(float, asinh, oi8);
+    check_uop(float, asinh, oi9);
+    check_uop(float, asinh, oi10);
+    check_uop(float, asinh, oi11);
+    check_uop(float, asinh, oi12);
+    check_uop(float, asinh, oi13);
+    check_uop(float, asinh, oi14);
+    check_uop(float, asinh, oi15);
+    check_uop(float, asinh, inf);
+    check_uop(float, asinh, ozero_pinf);
+    check_uop(float, asinh, ozero_ninf);
+    check_uop(float, asinh, czero_pinf);
+    check_uop(float, asinh, czero_ninf);
+
+    cout << "=====================" << endl;
+    check_uop(float, acosh, i1);
+    check_uop(float, acosh, i2);
+    check_uop(float, acosh, i5);
+    check_uop(float, acosh, i7);
+    check_uop(float, acosh, i8);
+    check_uop(float, acosh, oi1);
+    check_uop(float, acosh, oi2);
+    check_uop(float, acosh, oi5);
+    check_uop(float, acosh, oi7);
+    check_uop(float, acosh, oi8);
+
+    cout << "=====================" << endl;
+    check_uop(float, atanh, i10);
+    check_uop(float, atanh, i11);
+    check_uop(float, atanh, i12);
+    check_uop(float, atanh, i13);
+    check_uop(float, atanh, i14);
+    check_uop(float, atanh, i15);
+    check_uop(float, atanh, oi11);
+    check_uop(float, atanh, oi12);
+    check_uop(float, atanh, oi13);
+    check_uop(float, atanh, oi14);
+    check_uop(float, atanh, oi15);
 }
 
 int main() {
diff --git a/src/tests/interval/mpfp_interval.cpp b/src/tests/interval/mpfp_interval.cpp
index 27bf2c4b9..e5a0192ed 100644
--- a/src/tests/interval/mpfp_interval.cpp
+++ b/src/tests/interval/mpfp_interval.cpp
@@ -966,6 +966,68 @@ static void mpfp_interval_trans() {
     check_uop(mpfp, cot, ozero_ninf);
     check_uop(mpfp, cot, czero_pinf);
     check_uop(mpfp, cot, czero_ninf);
+
+    cout << "=====================" << endl;
+    check_uop(mpfp, asinh, i1);
+    check_uop(mpfp, asinh, i2);
+    check_uop(mpfp, asinh, i3);
+    check_uop(mpfp, asinh, i4);
+    check_uop(mpfp, asinh, i5);
+    check_uop(mpfp, asinh, i6);
+    check_uop(mpfp, asinh, i7);
+    check_uop(mpfp, asinh, i8);
+    check_uop(mpfp, asinh, i9);
+    check_uop(mpfp, asinh, i10);
+    check_uop(mpfp, asinh, i11);
+    check_uop(mpfp, asinh, i12);
+    check_uop(mpfp, asinh, i13);
+    check_uop(mpfp, asinh, i14);
+    check_uop(mpfp, asinh, i15);
+    check_uop(mpfp, asinh, oi1);
+    check_uop(mpfp, asinh, oi2);
+    check_uop(mpfp, asinh, oi3);
+    check_uop(mpfp, asinh, oi4);
+    check_uop(mpfp, asinh, oi5);
+    check_uop(mpfp, asinh, oi6);
+    check_uop(mpfp, asinh, oi7);
+    check_uop(mpfp, asinh, oi8);
+    check_uop(mpfp, asinh, oi9);
+    check_uop(mpfp, asinh, oi10);
+    check_uop(mpfp, asinh, oi11);
+    check_uop(mpfp, asinh, oi12);
+    check_uop(mpfp, asinh, oi13);
+    check_uop(mpfp, asinh, oi14);
+    check_uop(mpfp, asinh, oi15);
+    check_uop(mpfp, asinh, inf);
+    check_uop(mpfp, asinh, ozero_pinf);
+    check_uop(mpfp, asinh, ozero_ninf);
+    check_uop(mpfp, asinh, czero_pinf);
+    check_uop(mpfp, asinh, czero_ninf);
+
+    cout << "=====================" << endl;
+    check_uop(mpfp, acosh, i1);
+    check_uop(mpfp, acosh, i2);
+    check_uop(mpfp, acosh, i5);
+    check_uop(mpfp, acosh, i7);
+    check_uop(mpfp, acosh, i8);
+    check_uop(mpfp, acosh, oi1);
+    check_uop(mpfp, acosh, oi2);
+    check_uop(mpfp, acosh, oi5);
+    check_uop(mpfp, acosh, oi7);
+    check_uop(mpfp, acosh, oi8);
+
+    cout << "=====================" << endl;
+    check_uop(mpfp, atanh, i10);
+    check_uop(mpfp, atanh, i11);
+    check_uop(mpfp, atanh, i12);
+    check_uop(mpfp, atanh, i13);
+    check_uop(mpfp, atanh, i14);
+    check_uop(mpfp, atanh, i15);
+    check_uop(mpfp, atanh, oi11);
+    check_uop(mpfp, atanh, oi12);
+    check_uop(mpfp, atanh, oi13);
+    check_uop(mpfp, atanh, oi14);
+    check_uop(mpfp, atanh, oi15);
 }
 
 int main() {