diff --git a/src/types/initialization_vector.rs b/src/types/initialization_vector.rs
index 24bb213..779d3f1 100644
--- a/src/types/initialization_vector.rs
+++ b/src/types/initialization_vector.rs
@@ -52,7 +52,7 @@ impl InitializationVector {
     /// assert_eq!(InitializationVector::Missing.to_u128(), None);
     /// ```
     #[must_use]
-    pub const fn to_u128(&self) -> Option<u128> {
+    pub fn to_u128(&self) -> Option<u128> {
         match *self {
             Self::Aes128(v) => Some(u128::from_be_bytes(v)),
             Self::Number(n) => Some(n),
@@ -93,7 +93,7 @@ impl InitializationVector {
     ///
     /// [`MediaSegment`]: crate::MediaSegment
     #[must_use]
-    pub const fn to_slice(&self) -> Option<[u8; 0x10]> {
+    pub fn to_slice(&self) -> Option<[u8; 0x10]> {
         match &self {
             Self::Aes128(v) => Some(*v),
             Self::Number(v) => Some(v.to_be_bytes()),
diff --git a/src/types/key_format_versions.rs b/src/types/key_format_versions.rs
index b5f5980..518c7c5 100644
--- a/src/types/key_format_versions.rs
+++ b/src/types/key_format_versions.rs
@@ -144,7 +144,7 @@ impl KeyFormatVersions {
     /// the future this number might increase.
     #[inline]
     #[must_use]
-    pub const fn capacity(&self) -> usize { self.buffer.len() }
+    pub fn capacity(&self) -> usize { self.buffer.len() }
 
     /// Shortens the internal array to the provided length.
     ///