diff --git a/proj-sys/Cargo.toml b/proj-sys/Cargo.toml
index 659ff499..facc61f4 100644
--- a/proj-sys/Cargo.toml
+++ b/proj-sys/Cargo.toml
@@ -13,7 +13,7 @@ links = "proj"
 [dependencies]
 
 [build-dependencies]
-bindgen = "0.52.0"
+bindgen = "0.56.0"
 pkg-config = "0.3.17"
 cmake = "0.1"
 flate2 = "1.0.14"
diff --git a/proj-sys/build.rs b/proj-sys/build.rs
index efef0524..d8953785 100644
--- a/proj-sys/build.rs
+++ b/proj-sys/build.rs
@@ -49,6 +49,7 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     let bindings = bindgen::Builder::default()
         .clang_arg(format!("-I{}", include_path.to_string_lossy()))
         .trust_clang_mangling(false)
+        .size_t_is_usize(true)
         .blacklist_type("max_align_t")
         // The input header we would like to generate
         // bindings for.