diff --git a/src/lib.rs b/src/lib.rs
index 0990995..d8af02e 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -7,7 +7,7 @@ struct IRMetalLibBinaryOpaque;
 struct IRShaderReflectionOpaque;
 struct IRErrorOpaque;
 
-use std::mem::MaybeUninit;
+use std::{ffi::CStr, mem::MaybeUninit};
 
 #[repr(i32)]
 pub enum IRReflectionVersion {
@@ -325,9 +325,12 @@ impl<'lib> IRObject<'lib> {
         }
     }
 
-    pub fn gather_raytracing_intrinsics(&self, entry_point: &str) -> u64 {
+    pub fn gather_raytracing_intrinsics(&self, entry_point: &CStr) -> u64 {
         unsafe {
-            (self.funcs.gather_raytracing_intrinsics)(self.me, entry_point.as_ptr() as *const i8)
+            (self.funcs.gather_raytracing_intrinsics)(
+                self.me,
+                <*const u8>::cast::<i8>(entry_point.to_bytes_with_nul().as_ptr()),
+            )
         }
     }