diff --git a/pkgs/applications/version-management/mercurial/default.nix b/pkgs/applications/version-management/mercurial/default.nix
index 0fb1cdddfbaf..9dc3e0329e3c 100644
--- a/pkgs/applications/version-management/mercurial/default.nix
+++ b/pkgs/applications/version-management/mercurial/default.nix
@@ -28,6 +28,11 @@ let
       sha256 = "sha256-hvmGReRWWpJWmR3N4it3uOfSLKb7tgwfTNvYRpo4zB8=";
     };
 
+    patches = [
+      # Fix the type of libc buffer for aarch64-linux
+      ./fix-rhg-type-aarch64.patch
+    ];
+
     format = "other";
 
     passthru = { inherit python; }; # pass it so that the same version can be used in hg2git
diff --git a/pkgs/applications/version-management/mercurial/fix-rhg-type-aarch64.patch b/pkgs/applications/version-management/mercurial/fix-rhg-type-aarch64.patch
new file mode 100644
index 000000000000..84417b497c0a
--- /dev/null
+++ b/pkgs/applications/version-management/mercurial/fix-rhg-type-aarch64.patch
@@ -0,0 +1,12 @@
+diff --git a/rust/hg-core/src/lock.rs b/rust/hg-core/src/lock.rs
+--- a/rust/hg-core/src/lock.rs
++++ b/rust/hg-core/src/lock.rs
+@@ -145,7 +145,7 @@ lazy_static::lazy_static! {
+ 
+         /// Same as https://github.com/python/cpython/blob/v3.10.0/Modules/socketmodule.c#L5414
+         const BUFFER_SIZE: usize = 1024;
+-        let mut buffer = [0_i8; BUFFER_SIZE];
++        let mut buffer = [0 as libc::c_char; BUFFER_SIZE];
+         let hostname_bytes = unsafe {
+             let result = libc::gethostname(buffer.as_mut_ptr(), BUFFER_SIZE);
+             if result != 0 {