diff --git a/README.md b/README.md
index a4369a7..16c28ae 100644
--- a/README.md
+++ b/README.md
@@ -14,11 +14,11 @@ A somewhat safe Rust interface to the [ImageMagick](http://www.imagemagick.org/)
 * [Clang](https://clang.llvm.org) (version 3.5 or higher)
     - Or whatever version is dictated by [rust-bindgen](https://github.com/rust-lang/rust-bindgen)
 * Windows requires MSVC toolchain
-* Optionally `pkg-config`, to facilitate linking with ImageMagick. Or you can set linker parameters via environment variables.
+* Optionally `pkg-config`, to facilitate linking with ImageMagick. Or you can set linker parameters via environment variables as described in the next section.
 
 ## Build and Test
 
-Pretty simple for now.
+On FreeBSD, Linux, and macOS the following commands should suffice.
 
 ```shell
 $ cargo build
diff --git a/build.rs b/build.rs
index d5a4bb2..6db71ae 100644
--- a/build.rs
+++ b/build.rs
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2021 Nathan Fiedler
+ * Copyright 2016-2023 Nathan Fiedler
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -35,24 +35,10 @@ pub const PATH_SEPARATOR: &str = match cfg!(target_os = "windows") {
 };
 
 fn main() {
-    if cfg!(target_os = "freebsd") {
-        // pkg_config does not seem to work properly on FreeBSD, so
-        // hard-code the builder settings for the time being.
-        env_var_set_default(
-            "IMAGE_MAGICK_INCLUDE_DIRS",
-            "/usr/local/include/ImageMagick-7",
-        );
-        // Need to hack the linker flags as well.
-        env_var_set_default("IMAGE_MAGICK_LIB_DIRS", "/usr/local/lib");
-        env_var_set_default("IMAGE_MAGICK_LIBS", "MagickWand-7");
-    }
-
     let check_cppflags = Command::new("MagickCore-config").arg("--cppflags").output();
-    //on windows can not exec
     if check_cppflags.is_ok() {
         let cppflags = check_cppflags.unwrap().stdout;
         let cppflags = String::from_utf8(cppflags).unwrap();
-
         env_var_set_default("BINDGEN_EXTRA_CLANG_ARGS", &cppflags);
     }
 
@@ -79,10 +65,10 @@ fn main() {
     println!("cargo:rerun-if-env-changed=IMAGE_MAGICK_LIBS");
 
     let target = env::var("TARGET").unwrap();
-    let libs_env = env::var("IMAGE_MAGICK_LIBS").ok();
+    let libs_env = env::var("IMAGE_MAGICK_LIBS");
     let libs = match libs_env {
-        Some(ref v) => v.split(PATH_SEPARATOR).map(|x| x.to_owned()).collect(),
-        None => {
+        Ok(ref v) => v.split(PATH_SEPARATOR).map(|x| x.to_owned()).collect(),
+        Err(_) => {
             if target.contains("windows") {
                 vec!["CORE_RL_MagickWand_".to_string()]
             } else if target.contains("freebsd") {
@@ -210,11 +196,11 @@ fn find_image_magick_dir() -> Result<PathBuf, env::VarError> {
 
 fn determine_mode<T: AsRef<str>>(libdirs: &Vec<PathBuf>, libs: &[T]) -> &'static str {
     println!("cargo:rerun-if-env-changed=IMAGE_MAGICK_STATIC");
-    let kind = env::var("IMAGE_MAGICK_STATIC").ok();
+    let kind = env::var("IMAGE_MAGICK_STATIC");
     match kind.as_ref().map(|s| &s[..]) {
-        Some("0") => return "dylib",
-        Some(_) => return "static",
-        None => {}
+        Ok("0") => return "dylib",
+        Ok(_) => return "static",
+        Err(_) => {}
     }
 
     // See what files we actually have to link against, and see what our
@@ -272,7 +258,7 @@ fn run_pkg_config() -> pkg_config::Library {
         .unwrap()
         .success()
     {
-        panic!("MagickWand version must be less than 7.1");
+        panic!("MagickWand version must be less than {}", MAX_VERSION);
     }
     // We have to split the version check and the cflags/libs check because
     // you can't do both at the same time on RHEL (apparently).
diff --git a/src/wand/magick.rs b/src/wand/magick.rs
index 27a1556..a3cdbc8 100644
--- a/src/wand/magick.rs
+++ b/src/wand/magick.rs
@@ -73,7 +73,8 @@ impl MagickWand {
         }
     }
 
-    #[cfg(not(windows))]
+    // opt-in platforms that have resource limits support
+    #[cfg(any(target_os = "linux", target_os = "macos"))]
     pub fn set_resource_limit(resource: ResourceType, limit: u64) -> Result<()> {
         let result = unsafe {
             bindings::SetMagickResourceLimit(
diff --git a/tests/lib.rs b/tests/lib.rs
index 2f2f985..72c6a7c 100644
--- a/tests/lib.rs
+++ b/tests/lib.rs
@@ -385,7 +385,8 @@ fn test_negate_image() {
 }
 
 #[test]
-#[cfg(not(windows))]
+// opt-in platforms that have resource limits support
+#[cfg(any(target_os = "linux", target_os = "macos"))]
 fn test_resource_limits() {
     use magick_rust::ResourceType;
     START.call_once(|| {