diff --git a/lib/src/archive/entry/builder.rs b/lib/src/archive/entry/builder.rs
index 2384e8ec..92b907fc 100644
--- a/lib/src/archive/entry/builder.rs
+++ b/lib/src/archive/entry/builder.rs
@@ -33,7 +33,7 @@ impl EntryBuilder {
     /// # Returns
     ///
     /// A new [EntryBuilder].
-    pub fn new_dir(name: EntryName) -> Self {
+    pub const fn new_dir(name: EntryName) -> Self {
         Self {
             header: EntryHeader::for_dir(name),
             phsf: None,
diff --git a/lib/src/archive/entry/header.rs b/lib/src/archive/entry/header.rs
index 2ec88051..58438d7b 100644
--- a/lib/src/archive/entry/header.rs
+++ b/lib/src/archive/entry/header.rs
@@ -16,7 +16,7 @@ pub struct EntryHeader {
 }
 
 impl EntryHeader {
-    pub(crate) fn new_with_options(
+    pub(crate) const fn new_with_options(
         data_kind: DataKind,
         compression: Compression,
         encryption: Encryption,
@@ -34,7 +34,7 @@ impl EntryHeader {
         }
     }
 
-    pub(crate) fn new(data_kind: DataKind, path: EntryName) -> Self {
+    pub(crate) const fn new(data_kind: DataKind, path: EntryName) -> Self {
         Self::new_with_options(
             data_kind,
             Compression::No,
@@ -45,7 +45,7 @@ impl EntryHeader {
     }
 
     #[inline]
-    pub(crate) fn for_file(
+    pub(crate) const fn for_file(
         compression: Compression,
         encryption: Encryption,
         cipher_mode: CipherMode,
@@ -55,17 +55,17 @@ impl EntryHeader {
     }
 
     #[inline]
-    pub(crate) fn for_dir(path: EntryName) -> Self {
+    pub(crate) const fn for_dir(path: EntryName) -> Self {
         Self::new(DataKind::Directory, path)
     }
 
     #[inline]
-    pub(crate) fn for_symbolic_link(path: EntryName) -> Self {
+    pub(crate) const fn for_symbolic_link(path: EntryName) -> Self {
         Self::new(DataKind::SymbolicLink, path)
     }
 
     #[inline]
-    pub(crate) fn for_hard_link(path: EntryName) -> Self {
+    pub(crate) const fn for_hard_link(path: EntryName) -> Self {
         Self::new(DataKind::HardLink, path)
     }
 
@@ -75,22 +75,22 @@ impl EntryHeader {
     }
 
     #[inline]
-    pub fn data_kind(&self) -> DataKind {
+    pub const fn data_kind(&self) -> DataKind {
         self.data_kind
     }
 
     #[inline]
-    pub fn compression(&self) -> Compression {
+    pub const fn compression(&self) -> Compression {
         self.compression
     }
 
     #[inline]
-    pub fn encryption(&self) -> Encryption {
+    pub const fn encryption(&self) -> Encryption {
         self.encryption
     }
 
     #[inline]
-    pub fn cipher_mode(&self) -> CipherMode {
+    pub const fn cipher_mode(&self) -> CipherMode {
         self.cipher_mode
     }
 
@@ -142,7 +142,7 @@ pub struct SolidHeader {
 }
 
 impl SolidHeader {
-    pub(crate) fn new(
+    pub(crate) const fn new(
         compression: Compression,
         encryption: Encryption,
         cipher_mode: CipherMode,
@@ -157,22 +157,22 @@ impl SolidHeader {
     }
 
     #[inline]
-    pub fn compression(&self) -> Compression {
+    pub const fn compression(&self) -> Compression {
         self.compression
     }
 
     #[inline]
-    pub fn encryption(&self) -> Encryption {
+    pub const fn encryption(&self) -> Encryption {
         self.encryption
     }
 
     #[inline]
-    pub fn cipher_mode(&self) -> CipherMode {
+    pub const fn cipher_mode(&self) -> CipherMode {
         self.cipher_mode
     }
 
     #[inline]
-    pub fn to_bytes(&self) -> [u8; 5] {
+    pub const fn to_bytes(&self) -> [u8; 5] {
         [
             self.major,
             self.minor,
diff --git a/lib/src/archive/entry/meta.rs b/lib/src/archive/entry/meta.rs
index c34d64ee..73cb29c7 100644
--- a/lib/src/archive/entry/meta.rs
+++ b/lib/src/archive/entry/meta.rs
@@ -13,22 +13,22 @@ pub struct Metadata {
 impl Metadata {
     /// Compressed size of entry data
     #[inline]
-    pub fn compressed_size(&self) -> usize {
+    pub const fn compressed_size(&self) -> usize {
         self.compressed_size
     }
     /// Created time since unix epoch time of entry
     #[inline]
-    pub fn created(&self) -> Option<Duration> {
+    pub const fn created(&self) -> Option<Duration> {
         self.created
     }
     /// Modified time since unix epoch time of entry
     #[inline]
-    pub fn modified(&self) -> Option<Duration> {
+    pub const fn modified(&self) -> Option<Duration> {
         self.modified
     }
     /// A owner, group, and permissions for a entry
     #[inline]
-    pub fn permission(&self) -> Option<&Permission> {
+    pub const fn permission(&self) -> Option<&Permission> {
         self.permission.as_ref()
     }
 }
@@ -62,7 +62,7 @@ impl Permission {
     /// let perm = Permission::new(1000, "user".to_string(), 100, "group".to_string(), 0o755);
     /// ```
     #[inline]
-    pub fn new(uid: u64, uname: String, gid: u64, gname: String, permission: u16) -> Self {
+    pub const fn new(uid: u64, uname: String, gid: u64, gname: String, permission: u16) -> Self {
         Self {
             uid,
             uname,
@@ -82,7 +82,7 @@ impl Permission {
     /// assert_eq!(perm.uid(), 1000);
     /// ```
     #[inline]
-    pub fn uid(&self) -> u64 {
+    pub const fn uid(&self) -> u64 {
         self.uid
     }
 
@@ -112,7 +112,7 @@ impl Permission {
     /// assert_eq!(perm.gid(), 100);
     /// ```
     #[inline]
-    pub fn gid(&self) -> u64 {
+    pub const fn gid(&self) -> u64 {
         self.gid
     }
 
@@ -142,7 +142,7 @@ impl Permission {
     /// assert_eq!(perm.permissions(), 0o644);
     /// ```
     #[inline]
-    pub fn permissions(&self) -> u16 {
+    pub const fn permissions(&self) -> u16 {
         self.permission
     }
 
diff --git a/lib/src/archive/entry/options.rs b/lib/src/archive/entry/options.rs
index 92ddb99b..2a2474d6 100644
--- a/lib/src/archive/entry/options.rs
+++ b/lib/src/archive/entry/options.rs
@@ -295,7 +295,7 @@ impl ReadOption {
     /// let builder = ReadOption::builder();
     /// ```
     #[inline]
-    pub fn builder() -> ReadOptionBuilder {
+    pub const fn builder() -> ReadOptionBuilder {
         #[allow(deprecated)]
         ReadOptionBuilder::new()
     }
@@ -335,7 +335,7 @@ impl From<ReadOption> for ReadOptionBuilder {
 
 impl ReadOptionBuilder {
     #[deprecated(since = "0.2.0", note = "Use ReadOption::builder instead.")]
-    pub fn new() -> Self {
+    pub const fn new() -> Self {
         Self { password: None }
     }
 
diff --git a/lib/src/archive/read.rs b/lib/src/archive/read.rs
index 9590c22d..6672102f 100644
--- a/lib/src/archive/read.rs
+++ b/lib/src/archive/read.rs
@@ -157,7 +157,7 @@ impl<R: Read> Archive<R> {
     ///
     /// [ANXT]: ChunkType::ANXT
     #[inline]
-    pub fn next_archive(&self) -> bool {
+    pub const fn next_archive(&self) -> bool {
         self.next_archive
     }