diff --git a/include/librashader.h b/include/librashader.h
index e38c054..eb5ef5d 100644
--- a/include/librashader.h
+++ b/include/librashader.h
@@ -155,11 +155,9 @@ typedef struct libra_preset_param_t {
 typedef struct libra_preset_param_list_t {
   /// A pointer to the parameter
   const struct libra_preset_param_t *parameters;
-  /// The number of parameters in the list.
+  /// The number of parameters in the list. This field is readonly,
+  /// changing it will lead to undefined behaviour on free.
   uint64_t length;
-  /// For internal use only.
-  /// Changing this causes immediate undefined behaviour on freeing this parameter list.
-  uint64_t _internal_alloc;
 } libra_preset_param_list_t;
 
 #if defined(LIBRA_RUNTIME_OPENGL)
diff --git a/librashader-capi/src/presets.rs b/librashader-capi/src/presets.rs
index 2c7c8f5..8bafff4 100644
--- a/librashader-capi/src/presets.rs
+++ b/librashader-capi/src/presets.rs
@@ -14,11 +14,10 @@ const _: () = crate::assert_thread_safe::<ShaderPreset>();
 pub struct libra_preset_param_list_t {
     /// A pointer to the parameter
     pub parameters: *const libra_preset_param_t,
-    /// The number of parameters in the list.
+    /// The number of parameters in the list. This field
+    /// is readonly, and changing it will lead to undefined
+    /// behaviour on free.
     pub length: u64,
-    /// For internal use only.
-    /// Changing this causes immediate undefined behaviour on freeing this parameter list.
-    pub _internal_alloc: u64,
 }
 
 /// A preset parameter.
@@ -226,7 +225,6 @@ extern_fn! {
             out.write(MaybeUninit::new(libra_preset_param_list_t {
                 parameters: parts,
                 length: len as u64,
-                _internal_alloc: 0,
             }));
         }
     }