diff --git a/.cirrus.yml b/.cirrus.yml
index dbd0b15aca..522bdafcdb 100644
--- a/.cirrus.yml
+++ b/.cirrus.yml
@@ -9,7 +9,7 @@ env:
   RUSTFLAGS: -D warnings
   RUSTDOCFLAGS: -D warnings
   TOOL: cargo
-  MSRV: 1.63.0
+  MSRV: 1.65.0
   ZFLAGS:
 
 # Tests that don't require executing the build binaries
@@ -137,7 +137,7 @@ task:
     - curl --proto '=https' --tlsv1.2 -sSf -o rustup.sh https://sh.rustup.rs
     - sh rustup.sh -y --profile=minimal --default-toolchain $MSRV
     - . $HOME/.cargo/env
-    - cargo install cross --version 0.2.1 # cross 0.2.2 bumped the MSRV to 1.58.1
+    - cargo install cross --version 0.2.5
   << : *TEST
   before_cache_script: rm -rf $CARGO_HOME/registry/index
 
@@ -146,7 +146,7 @@ task:
   matrix:
     - name: Linux aarch64
       arm_container:
-        image: rust:1.63.0
+        image: rust:1.65.0
         cpu: 1
       depends_on:
         - FreeBSD 14 amd64 & i686
@@ -160,13 +160,13 @@ task:
         TARGET: aarch64-unknown-linux-gnu
     - name: Linux x86_64
       container:
-        image: rust:1.63.0
+        image: rust:1.65.0
         cpu: 1
       env:
         TARGET: x86_64-unknown-linux-gnu
     - name: Linux x86_64 musl
       container:
-        image: rust:1.63.0
+        image: rust:1.65.0
         cpu: 1
       depends_on:
         - FreeBSD 14 amd64 & i686
@@ -199,7 +199,7 @@ task:
 # Tasks for cross-compiling, but no testing
 task:
   container:
-    image: rust:1.63.0
+    image: rust:1.65.0
     cpu: 1
   depends_on:
     - FreeBSD 14 amd64 & i686
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 85bd94b2a3..7de03da0bf 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -32,8 +32,9 @@ This project adheres to [Semantic Versioning](https://semver.org/).
 
 ### Changed
 
-- The MSRV is now 1.63
+- The MSRV is now 1.65
   ([#1862](https://github.com/nix-rust/nix/pull/1862))
+  ([#2104](https://github.com/nix-rust/nix/pull/2104))
 - The epoll interface now uses a type.
   ([#1882](https://github.com/nix-rust/nix/pull/1882))
 - With I/O-safe type applied in `pty::OpenptyResult` and `pty::ForkptyResult`,
diff --git a/Cargo.toml b/Cargo.toml
index 8cfd38fbc3..010c9f895b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -3,7 +3,7 @@ name        = "nix"
 description = "Rust friendly bindings to *nix APIs"
 edition     = "2021"
 version     = "0.26.1"
-rust-version = "1.63"
+rust-version = "1.65"
 authors     = ["The nix-rust Project Developers"]
 repository  = "https://github.com/nix-rust/nix"
 license     = "MIT"
diff --git a/README.md b/README.md
index 3c528b6665..e172de2750 100644
--- a/README.md
+++ b/README.md
@@ -104,7 +104,7 @@ The following targets are supported by `nix`:
 
 ## Minimum Supported Rust Version (MSRV)
 
-nix is supported on Rust 1.63 and higher.  Its MSRV will not be
+nix is supported on Rust 1.65 and higher.  Its MSRV will not be
 changed in the future without bumping the major or minor version.
 
 ## Contributing
diff --git a/src/sys/ioctl/linux.rs b/src/sys/ioctl/linux.rs
index 669d517906..610b8ddac0 100644
--- a/src/sys/ioctl/linux.rs
+++ b/src/sys/ioctl/linux.rs
@@ -1,3 +1,5 @@
+use cfg_if::cfg_if;
+
 /// The datatype used for the ioctl number
 #[cfg(any(target_os = "android", target_env = "musl"))]
 #[doc(hidden)]
@@ -14,48 +16,41 @@ pub const NRBITS: ioctl_num_type = 8;
 #[doc(hidden)]
 pub const TYPEBITS: ioctl_num_type = 8;
 
-#[cfg(any(
-    target_arch = "mips",
-    target_arch = "mips64",
-    target_arch = "powerpc",
-    target_arch = "powerpc64",
-    target_arch = "sparc64"
-))]
-mod consts {
-    #[doc(hidden)]
-    pub const NONE: u8 = 1;
-    #[doc(hidden)]
-    pub const READ: u8 = 2;
-    #[doc(hidden)]
-    pub const WRITE: u8 = 4;
-    #[doc(hidden)]
-    pub const SIZEBITS: u8 = 13;
-    #[doc(hidden)]
-    pub const DIRBITS: u8 = 3;
-}
-
-// "Generic" ioctl protocol
-#[cfg(any(
-    target_arch = "x86",
-    target_arch = "arm",
-    target_arch = "s390x",
-    target_arch = "x86_64",
-    target_arch = "aarch64",
-    target_arch = "riscv32",
-    target_arch = "riscv64",
-    target_arch = "loongarch64"
-))]
-mod consts {
-    #[doc(hidden)]
-    pub const NONE: u8 = 0;
-    #[doc(hidden)]
-    pub const READ: u8 = 2;
-    #[doc(hidden)]
-    pub const WRITE: u8 = 1;
-    #[doc(hidden)]
-    pub const SIZEBITS: u8 = 14;
-    #[doc(hidden)]
-    pub const DIRBITS: u8 = 2;
+cfg_if! {
+    if #[cfg(any(
+        target_arch = "mips",
+        target_arch = "mips64",
+        target_arch = "powerpc",
+        target_arch = "powerpc64",
+        target_arch = "sparc64"
+    ))] {
+        mod consts {
+            #[doc(hidden)]
+            pub const NONE: u8 = 1;
+            #[doc(hidden)]
+            pub const READ: u8 = 2;
+            #[doc(hidden)]
+            pub const WRITE: u8 = 4;
+            #[doc(hidden)]
+            pub const SIZEBITS: u8 = 13;
+            #[doc(hidden)]
+            pub const DIRBITS: u8 = 3;
+        }
+    } else {
+        // "Generic" ioctl protocol
+        mod consts {
+            #[doc(hidden)]
+            pub const NONE: u8 = 0;
+            #[doc(hidden)]
+            pub const READ: u8 = 2;
+            #[doc(hidden)]
+            pub const WRITE: u8 = 1;
+            #[doc(hidden)]
+            pub const SIZEBITS: u8 = 14;
+            #[doc(hidden)]
+            pub const DIRBITS: u8 = 2;
+        }
+    }
 }
 
 pub use self::consts::*;