diff --git a/dpe/build.rs b/dpe/build.rs
index 53c244da..69062feb 100644
--- a/dpe/build.rs
+++ b/dpe/build.rs
@@ -20,10 +20,16 @@ fn main() {
     let max_handles_str = format!("pub const MAX_HANDLES: usize = {};", arbitrary_max_handles);
 
     let dest_path = PathBuf::from(&dest_path);
-    if dest_path.exists()
-        && std::fs::read_to_string(&dest_path).unwrap_or_default() != max_handles_str
-    {
-        std::fs::write(&dest_path, max_handles_str).unwrap();
+    match std::fs::read_to_string(&dest_path) {
+        // arbitrary_max_handles.rs changed so overwrite it's contents.
+        Ok(handles) if handles != max_handles_str => {
+            std::fs::write(&dest_path, max_handles_str).unwrap();
+        }
+        // arbitrary_max_handles.rs does not exist.
+        Err(_) => {
+            std::fs::write(&dest_path, max_handles_str).unwrap();
+        }
+        _ => (),
     }
     println!("cargo:rerun-if-changed={}", dest_path.display());
 }