diff --git a/src/lib.rs b/src/lib.rs
index aee3ea9..70996a4 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -957,14 +957,14 @@ macro_rules! impl_ranged {
 
             /// Returns `true` if the value is the niche value.
             #[inline(always)]
-            pub const fn is_none(self) -> bool {
+            pub const fn is_none(&self) -> bool {
                 <$type<MIN, MAX> as $crate::traits::RangeIsValid>::ASSERT;
                 self.get().is_none()
             }
 
             /// Returns `true` if the value is not the niche value.
             #[inline(always)]
-            pub const fn is_some(self) -> bool {
+            pub const fn is_some(&self) -> bool {
                 <$type<MIN, MAX> as $crate::traits::RangeIsValid>::ASSERT;
                 self.get().is_some()
             }
diff --git a/src/tests.rs b/src/tests.rs
index e9a6ff7..2345ad4 100644
--- a/src/tests.rs
+++ b/src/tests.rs
@@ -1,11 +1,11 @@
 use std::hash::Hash;
 
 use crate::{
-    IntErrorKind, OptionRangedI128, OptionRangedI16, OptionRangedI32, OptionRangedI64,
-    OptionRangedI8, OptionRangedIsize, OptionRangedU128, OptionRangedU16, OptionRangedU32,
-    OptionRangedU64, OptionRangedU8, OptionRangedUsize, ParseIntError, RangedI128, RangedI16,
-    RangedI32, RangedI64, RangedI8, RangedIsize, RangedU128, RangedU16, RangedU32, RangedU64,
-    RangedU8, RangedUsize, TryFromIntError,
+    IntErrorKind, OptionRangedI8, OptionRangedI16, OptionRangedI32, OptionRangedI64,
+    OptionRangedI128, OptionRangedIsize, OptionRangedU8, OptionRangedU16, OptionRangedU32,
+    OptionRangedU64, OptionRangedU128, OptionRangedUsize, ParseIntError, RangedI8, RangedI16,
+    RangedI32, RangedI64, RangedI128, RangedIsize, RangedU8, RangedU16, RangedU32, RangedU64,
+    RangedU128, RangedUsize, TryFromIntError,
 };
 
 macro_rules! if_signed {
@@ -63,12 +63,9 @@ fn errors() {
         "number would be zero for non-zero type"
     );
     assert_eq!(
-        format!(
-            "{:?}",
-            ParseIntError {
-                kind: IntErrorKind::Empty
-            }
-        ),
+        format!("{:?}", ParseIntError {
+            kind: IntErrorKind::Empty
+        }),
         "ParseIntError { kind: Empty }"
     );
     assert_eq!(
@@ -147,6 +144,18 @@ macro_rules! tests {
             assert!($opt::<5, 10>::None.is_none());
         )*}
 
+        #[test]
+        fn is_some_by_ref() {$(
+            let value = $opt::<5, 10>::Some($t::<5, 10>::MAX);
+            assert!($opt::is_some(&value));
+        )*}
+
+        #[test]
+        fn is_none_by_ref() {$(
+            let value = $opt::<5, 10>::None;
+            assert!($opt::is_none(&value));
+        )*}
+
         #[test]
         fn default() {$(
             assert_eq!($opt::<5, 10>::default(), $opt::<5, 10>::None);
diff --git a/src/traits.rs b/src/traits.rs
index d1b69ac..279142e 100644
--- a/src/traits.rs
+++ b/src/traits.rs
@@ -1,6 +1,6 @@
 use crate::{
-    RangedI128, RangedI16, RangedI32, RangedI64, RangedI8, RangedIsize, RangedU128, RangedU16,
-    RangedU32, RangedU64, RangedU8, RangedUsize,
+    RangedI8, RangedI16, RangedI32, RangedI64, RangedI128, RangedIsize, RangedU8, RangedU16,
+    RangedU32, RangedU64, RangedU128, RangedUsize,
 };
 
 macro_rules! declare_traits {