diff --git a/.cargo/config.toml b/.cargo/config.toml
index 6265152b..dfe0a638 100644
--- a/.cargo/config.toml
+++ b/.cargo/config.toml
@@ -1,3 +1,6 @@
+[alias]
+xtask = "run --manifest-path xtask/Cargo.toml --"
+
 [target.'cfg(all(target_os = "linux", target_arch = "aarch64"))']
 runner = "qemu-aarch64" # May need to remove this if targeting AArch64 from an AArch64 Linux box
 
diff --git a/.github/workflows/deploy.yml b/.github/workflows/deploy.yml
index 0f4062d6..f02786e3 100644
--- a/.github/workflows/deploy.yml
+++ b/.github/workflows/deploy.yml
@@ -90,7 +90,6 @@ jobs:
         run: |
           mkdir -p "target/${{ matrix.target }}/release"
           mv target/oxipng "target/${{ matrix.target }}/release"
-          mv target/debug/assets "target/${{ matrix.target }}/release"
           cargo install --locked cargo-deb
           cargo deb --target "${{ matrix.target }}" --no-build --no-strip
 
diff --git a/Cargo.lock b/Cargo.lock
index 3154415b..0c560d0e 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -148,16 +148,6 @@ version = "0.7.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "afb84c814227b90d6895e01398aee0d8033c00e7466aca416fb6a8e0eb19d8a7"
 
-[[package]]
-name = "clap_mangen"
-version = "0.2.24"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fbae9cbfdc5d4fa8711c09bd7b83f644cb48281ac35bf97af3e47b0675864bdf"
-dependencies = [
- "clap",
- "roff",
-]
-
 [[package]]
 name = "colorchoice"
 version = "1.0.3"
@@ -412,7 +402,6 @@ version = "9.1.2"
 dependencies = [
  "bitvec",
  "clap",
- "clap_mangen",
  "crossbeam-channel",
  "env_logger",
  "filetime",
@@ -484,12 +473,6 @@ dependencies = [
  "bytemuck",
 ]
 
-[[package]]
-name = "roff"
-version = "0.2.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "88f8660c1ff60292143c98d08fc6e2f654d722db50410e3f3797d40baaf9d8f3"
-
 [[package]]
 name = "rustc-hash"
 version = "2.0.0"
diff --git a/Cargo.toml b/Cargo.toml
index 3cae1cc9..9969ee2f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -13,6 +13,7 @@ exclude = [
   "Dockerfile",
   "scripts/*",
   "tests/*",
+  "xtask/*",
 ]
 homepage = "https://github.com/shssoichiro/oxipng"
 license = "MIT"
@@ -77,10 +78,6 @@ default-features = false
 features = ["png"]
 version = "0.25.5"
 
-[build-dependencies]
-clap = "4.5.21"
-clap_mangen = "0.2.24"
-
 [features]
 binary = ["dep:clap", "dep:glob", "dep:env_logger"]
 default = ["binary", "parallel", "zopfli", "filetime"]
@@ -105,7 +102,7 @@ panic = "abort"
 [package.metadata.deb]
 assets = [
     ["target/release/oxipng", "usr/bin/", "755"],
-    ["target/release/assets/oxipng.1", "usr/share/man/man1/", "644"],
+    ["target/xtask/mangen/manpages/oxipng.1", "usr/share/man/man1/", "644"],
     ["README.md", "usr/share/doc/oxipng/", "644"],
     ["CHANGELOG.md", "usr/share/doc/oxipng/", "644"],
 ]
diff --git a/MANUAL.txt b/MANUAL.txt
index 8c6dba9d..c77410aa 100644
--- a/MANUAL.txt
+++ b/MANUAL.txt
@@ -168,6 +168,12 @@ Options:
           Use the much slower but stronger Zopfli compressor for main compression trials.
           Recommended use is with '-o max' and '--fast'.
 
+      --zi <iterations>
+          Set the number of iterations to use for Zopfli compression. Using fewer iterations may
+          speed up compression for large files. This option requires '--zopfli' to be set.
+          
+          [default: 15]
+
       --timeout <secs>
           Maximum amount of time, in seconds, to spend on optimizations. Oxipng will check the
           timeout before each transformation or compression trial, and will stop trying to optimize
diff --git a/build.rs b/build.rs
deleted file mode 100644
index 12b545b1..00000000
--- a/build.rs
+++ /dev/null
@@ -1,40 +0,0 @@
-use std::{
-    env,
-    fs::File,
-    io::{BufWriter, Error},
-    path::Path,
-};
-
-use clap_mangen::Man;
-
-include!("src/cli.rs");
-
-fn build_manpages(outdir: &Path) -> Result<(), Error> {
-    let app = build_command();
-
-    let file = Path::new(&outdir).join("oxipng.1");
-    let mut file = BufWriter::new(File::create(file)?);
-
-    Man::new(app).render(&mut file)?;
-
-    Ok(())
-}
-
-fn main() -> Result<(), Error> {
-    println!("cargo:rerun-if-changed=src/cli.rs");
-    println!("cargo:rerun-if-changed=src/display_chunks.rs");
-
-    // Create `target/<debug|release>/assets/` folder.
-    let outdir = match env::var_os("OUT_DIR") {
-        None => return Ok(()),
-        Some(outdir) => outdir,
-    };
-    let out_path = PathBuf::from(outdir);
-    let mut path = out_path.ancestors().nth(3).unwrap().to_owned();
-    path.push("assets");
-    std::fs::create_dir_all(&path).unwrap();
-
-    build_manpages(&path)?;
-
-    Ok(())
-}
diff --git a/scripts/manual.sh b/scripts/manual.sh
index f8e2f4cc..be1fe60a 100755
--- a/scripts/manual.sh
+++ b/scripts/manual.sh
@@ -1,5 +1,6 @@
-#!/bin/bash
+#!/bin/sh -eu
 cargo build
+cargo xtask mangen
 
 ./target/debug/oxipng -V > MANUAL.txt
 #Redirect all streams to prevent detection of the terminal width and force an internal default of 100
diff --git a/xtask/Cargo.lock b/xtask/Cargo.lock
new file mode 100644
index 00000000..3ea263df
--- /dev/null
+++ b/xtask/Cargo.lock
@@ -0,0 +1,200 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "anstream"
+version = "0.6.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8acc5369981196006228e28809f761875c0327210a891e941f4c683b3a99529b"
+dependencies = [
+ "anstyle",
+ "anstyle-parse",
+ "anstyle-query",
+ "anstyle-wincon",
+ "colorchoice",
+ "is_terminal_polyfill",
+ "utf8parse",
+]
+
+[[package]]
+name = "anstyle"
+version = "1.0.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "55cc3b69f167a1ef2e161439aa98aed94e6028e5f9a59be9a6ffb47aef1651f9"
+
+[[package]]
+name = "anstyle-parse"
+version = "0.2.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3b2d16507662817a6a20a9ea92df6652ee4f94f914589377d69f3b21bc5798a9"
+dependencies = [
+ "utf8parse",
+]
+
+[[package]]
+name = "anstyle-query"
+version = "1.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "79947af37f4177cfead1110013d678905c37501914fba0efea834c3fe9a8d60c"
+dependencies = [
+ "windows-sys",
+]
+
+[[package]]
+name = "anstyle-wincon"
+version = "3.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2109dbce0e72be3ec00bed26e6a7479ca384ad226efdd66db8fa2e3a38c83125"
+dependencies = [
+ "anstyle",
+ "windows-sys",
+]
+
+[[package]]
+name = "clap"
+version = "4.5.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fb3b4b9e5a7c7514dfa52869339ee98b3156b0bfb4e8a77c4ff4babb64b1604f"
+dependencies = [
+ "clap_builder",
+]
+
+[[package]]
+name = "clap_builder"
+version = "4.5.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b17a95aa67cc7b5ebd32aa5370189aa0d79069ef1c64ce893bd30fb24bff20ec"
+dependencies = [
+ "anstream",
+ "anstyle",
+ "clap_lex",
+ "strsim",
+]
+
+[[package]]
+name = "clap_lex"
+version = "0.7.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "afb84c814227b90d6895e01398aee0d8033c00e7466aca416fb6a8e0eb19d8a7"
+
+[[package]]
+name = "clap_mangen"
+version = "0.2.24"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fbae9cbfdc5d4fa8711c09bd7b83f644cb48281ac35bf97af3e47b0675864bdf"
+dependencies = [
+ "clap",
+ "roff",
+]
+
+[[package]]
+name = "colorchoice"
+version = "1.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5b63caa9aa9397e2d9480a9b13673856c78d8ac123288526c37d7839f2a86990"
+
+[[package]]
+name = "is_terminal_polyfill"
+version = "1.70.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7943c866cc5cd64cbc25b2e01621d07fa8eb2a1a23160ee81ce38704e97b8ecf"
+
+[[package]]
+name = "roff"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "88f8660c1ff60292143c98d08fc6e2f654d722db50410e3f3797d40baaf9d8f3"
+
+[[package]]
+name = "strsim"
+version = "0.11.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7da8b5736845d9f2fcb837ea5d9e2628564b3b043a70948a3f0b778838c5fb4f"
+
+[[package]]
+name = "utf8parse"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "06abde3611657adf66d383f00b093d7faecc7fa57071cce2578660c9f1010821"
+
+[[package]]
+name = "windows-sys"
+version = "0.59.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e38bc4d79ed67fd075bcc251a1c39b32a1776bbe92e5bef1f0bf1f8c531853b"
+dependencies = [
+ "windows-targets",
+]
+
+[[package]]
+name = "windows-targets"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9b724f72796e036ab90c1021d4780d4d3d648aca59e491e6b98e725b84e99973"
+dependencies = [
+ "windows_aarch64_gnullvm",
+ "windows_aarch64_msvc",
+ "windows_i686_gnu",
+ "windows_i686_gnullvm",
+ "windows_i686_msvc",
+ "windows_x86_64_gnu",
+ "windows_x86_64_gnullvm",
+ "windows_x86_64_msvc",
+]
+
+[[package]]
+name = "windows_aarch64_gnullvm"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "32a4622180e7a0ec044bb555404c800bc9fd9ec262ec147edd5989ccd0c02cd3"
+
+[[package]]
+name = "windows_aarch64_msvc"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "09ec2a7bb152e2252b53fa7803150007879548bc709c039df7627cabbd05d469"
+
+[[package]]
+name = "windows_i686_gnu"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8e9b5ad5ab802e97eb8e295ac6720e509ee4c243f69d781394014ebfe8bbfa0b"
+
+[[package]]
+name = "windows_i686_gnullvm"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0eee52d38c090b3caa76c563b86c3a4bd71ef1a819287c19d586d7334ae8ed66"
+
+[[package]]
+name = "windows_i686_msvc"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "240948bc05c5e7c6dabba28bf89d89ffce3e303022809e73deaefe4f6ec56c66"
+
+[[package]]
+name = "windows_x86_64_gnu"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "147a5c80aabfbf0c7d901cb5895d1de30ef2907eb21fbbab29ca94c5b08b1a78"
+
+[[package]]
+name = "windows_x86_64_gnullvm"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "24d5b23dc417412679681396f2b49f3de8c1473deb516bd34410872eff51ed0d"
+
+[[package]]
+name = "windows_x86_64_msvc"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "589f6da84c646204747d1270a2a5661ea66ed1cced2631d546fdfb155959f9ec"
+
+[[package]]
+name = "xtask"
+version = "0.1.0"
+dependencies = [
+ "clap",
+ "clap_mangen",
+]
diff --git a/xtask/Cargo.toml b/xtask/Cargo.toml
new file mode 100644
index 00000000..4d0d24a6
--- /dev/null
+++ b/xtask/Cargo.toml
@@ -0,0 +1,10 @@
+[package]
+name = "xtask"
+description = "xtasks for the Oxipng project: https://github.com/matklad/cargo-xtask"
+version = "0.1.0"
+edition = "2021"
+publish = false
+
+[dependencies]
+clap = "4.5.21"
+clap_mangen = "0.2.24"
diff --git a/xtask/src/main.rs b/xtask/src/main.rs
new file mode 100644
index 00000000..13a34fce
--- /dev/null
+++ b/xtask/src/main.rs
@@ -0,0 +1,26 @@
+use std::{env, error::Error, fs, fs::File, io::BufWriter};
+
+use clap_mangen::Man;
+
+include!("../../src/cli.rs");
+
+fn main() -> Result<(), Box<dyn Error>> {
+    match &*env::args().nth(1).ok_or("No xtask to run provided")? {
+        "mangen" => build_manpages(),
+        _ => Err("Unknown xtask".into()),
+    }
+}
+
+fn build_manpages() -> Result<(), Box<dyn Error>> {
+    // Put manpages in <working directory>/target/xtask/mangen/manpages. Our working directory is
+    // expected to be the root of the repository due to the xtask invocation alias
+    let manpages_dir = env::current_dir()?.join("target/xtask/mangen/manpages");
+    fs::create_dir_all(&manpages_dir)?;
+
+    let mut man_file = BufWriter::new(File::create(manpages_dir.join("oxipng.1"))?);
+    Man::new(build_command()).render(&mut man_file)?;
+
+    println!("Manpages generated in {}", manpages_dir.display());
+
+    Ok(())
+}