diff --git a/textproc/bookokrat/files/patch-cargo-crates_mupdf-sys-0.6.0_build.rs b/textproc/bookokrat/files/patch-cargo-crates_mupdf-sys-0.6.0_build.rs
index 4c2f9d1061f0..e603119b4f6a 100644
--- a/textproc/bookokrat/files/patch-cargo-crates_mupdf-sys-0.6.0_build.rs
+++ b/textproc/bookokrat/files/patch-cargo-crates_mupdf-sys-0.6.0_build.rs
@@ -1,10 +1,20 @@
 --- cargo-crates/mupdf-sys-0.6.0/build.rs.orig	2006-07-24 01:21:28 UTC
 +++ cargo-crates/mupdf-sys-0.6.0/build.rs
 @@ -185,6 +185,7 @@ fn generate_bindings(target: &Target, path: &Path, sys
      builder = builder
          .allowlist_recursively(false)
          .allowlist_type("wchar_t")
 +        .allowlist_type("___wchar_t")
          .allowlist_type("FILE")
          .opaque_type("FILE")
          .allowlist_item("max_align_t")
+@@ -336,7 +337,8 @@ impl Target {
+             os: env::var("CARGO_CFG_TARGET_OS")?,
+             env: env::var("CARGO_CFG_TARGET_ENV")?,
+ 
+-            features: env::var("CARGO_CFG_TARGET_FEATURE")?
++            features: env::var("CARGO_CFG_TARGET_FEATURE")
++                .unwrap_or_default()
+                 .split(',')
+                 .map(str::to_owned)
+                 .collect(),