diff --git a/fixed_wide/src/fixed.rs b/fixed_wide/src/fixed.rs
index 14c8245..635b2e2 100644
--- a/fixed_wide/src/fixed.rs
+++ b/fixed_wide/src/fixed.rs
@@ -585,6 +585,9 @@ macro_rules! impl_fix_rhs_lt_lhs_not_const_generic{
 			paste::item!{
 				#[inline]
 				pub fn [<fix_ $rhs>](self)->Fixed<$rhs,{$rhs*32}>{
+					let max=bnum::cast::As::as_::<BInt::<$lhs>>(BInt::<$rhs>::MAX).shl(($lhs-$rhs)*32);
+					let min=bnum::cast::As::as_::<BInt::<$lhs>>(BInt::<$rhs>::MIN).shl(($lhs-$rhs)*32);
+					assert!(min<self.bits&&self.bits<max,"Truncation detected");
 					Fixed::from_bits(bnum::cast::As::as_::<BInt::<$rhs>>(self.bits.shr(($lhs-$rhs)*32)))
 				}
 			}