diff --git a/crates/bevy_legion/legion_systems/src/resource.rs b/crates/bevy_legion/legion_systems/src/resource.rs
index 3d07f19f25..b8ef714476 100644
--- a/crates/bevy_legion/legion_systems/src/resource.rs
+++ b/crates/bevy_legion/legion_systems/src/resource.rs
@@ -107,6 +107,9 @@ pub trait ResourceSet: Send + Sync {
     {
         unsafe { Self::fetch_unchecked(resources) }
     }
+
+    fn read_types() -> Vec<ResourceTypeId>;
+    fn write_types() -> Vec<ResourceTypeId>;
 }
 
 /// Blanket trait for resource types.
@@ -365,6 +368,8 @@ impl ResourceSet for () {
     type PreparedResources = ();
 
     unsafe fn fetch_unchecked(_: &Resources) {}
+    fn read_types() -> Vec<ResourceTypeId> { Vec::new() }
+    fn write_types() -> Vec<ResourceTypeId> { Vec::new() }
 }
 
 impl<T: Resource> ResourceSet for Read<T> {
@@ -376,6 +381,10 @@ impl<T: Resource> ResourceSet for Read<T> {
             .unwrap_or_else(|| panic!("Failed to fetch resource!: {}", std::any::type_name::<T>()));
         PreparedRead::new(resource.deref() as *const T)
     }
+    fn read_types() -> Vec<ResourceTypeId> {
+        vec![ResourceTypeId::of::<T>()]
+    }
+    fn write_types() -> Vec<ResourceTypeId> { Vec::new() }
 }
 impl<T: Resource> ResourceSet for Write<T> {
     type PreparedResources = PreparedWrite<T>;
@@ -386,6 +395,12 @@ impl<T: Resource> ResourceSet for Write<T> {
             .unwrap_or_else(|| panic!("Failed to fetch resource!: {}", std::any::type_name::<T>()));
         PreparedWrite::new(resource.deref_mut() as *mut T)
     }
+    fn read_types() -> Vec<ResourceTypeId> {
+        Vec::new()
+    }
+    fn write_types() -> Vec<ResourceTypeId> {
+        vec![ResourceTypeId::of::<T>()]
+    }
 }
 
 macro_rules! impl_resource_tuple {
@@ -398,6 +413,16 @@ macro_rules! impl_resource_tuple {
             unsafe fn fetch_unchecked(resources: &Resources) -> Self::PreparedResources {
                 ($( $ty::fetch_unchecked(resources), )*)
             }
+            fn read_types() -> Vec<ResourceTypeId> {
+                let mut vec = vec![];
+                $( vec.extend($ty::read_types()); )*
+                vec
+            }
+            fn write_types() -> Vec<ResourceTypeId> {
+                let mut vec = vec![];
+                $( vec.extend($ty::write_types()); )*
+                vec
+            }
         }
     };
 }
diff --git a/crates/bevy_legion/legion_systems/src/system.rs b/crates/bevy_legion/legion_systems/src/system.rs
index 94a72ee208..68c96f4f1a 100644
--- a/crates/bevy_legion/legion_systems/src/system.rs
+++ b/crates/bevy_legion/legion_systems/src/system.rs
@@ -32,8 +32,8 @@ use legion_core::{
 #[derive(Derivative, Debug, Clone)]
 #[derivative(Default(bound = ""))]
 pub struct Access<T> {
-    reads: Vec<T>,
-    writes: Vec<T>,
+    pub reads: Vec<T>,
+    pub writes: Vec<T>,
 }
 
 /// Structure describing the resource and component access conditions of the system.
diff --git a/crates/bevy_legion/legion_systems/src/system_fn.rs b/crates/bevy_legion/legion_systems/src/system_fn.rs
index 5ef5bbfaac..3fe297ee58 100644
--- a/crates/bevy_legion/legion_systems/src/system_fn.rs
+++ b/crates/bevy_legion/legion_systems/src/system_fn.rs
@@ -22,8 +22,13 @@ where
     R: EntityFilter + Sync + 'static,
     X: ResourceSet<PreparedResources = X> + 'static,
 {
-    let resource_access: Access<ResourceTypeId> = Access::default();
-    let component_access: Access<ComponentTypeId> = Access::default();
+    let mut resource_access: Access<ResourceTypeId> = Access::default();
+    resource_access.reads.extend(X::read_types().iter());
+    resource_access.writes.extend(X::write_types().iter());
+
+    let mut component_access: Access<ComponentTypeId> = Access::default();
+    component_access.reads.extend(Q::read_types().iter());
+    component_access.writes.extend(Q::write_types().iter());
 
     let run_fn = SystemFnWrapper(
         move |_,
diff --git a/crates/bevy_legion/legion_systems/src/system_fn_types.rs b/crates/bevy_legion/legion_systems/src/system_fn_types.rs
index 507ff48d7a..ae79b44357 100644
--- a/crates/bevy_legion/legion_systems/src/system_fn_types.rs
+++ b/crates/bevy_legion/legion_systems/src/system_fn_types.rs
@@ -1,4 +1,4 @@
-use crate::resource::{PreparedRead, ResourceSet, Resources, Resource, PreparedWrite};
+use crate::resource::{PreparedRead, ResourceSet, Resources, Resource, PreparedWrite, ResourceTypeId};
 use std::ops::{Deref, DerefMut};
 
 impl<T: Resource> ResourceSet for PreparedRead<T> {
@@ -10,6 +10,10 @@ impl<T: Resource> ResourceSet for PreparedRead<T> {
             .unwrap_or_else(|| panic!("Failed to fetch resource!: {}", std::any::type_name::<T>()));
         PreparedRead::new(resource.deref() as *const T)
     }
+    fn read_types() -> Vec<ResourceTypeId> {
+        vec![ResourceTypeId::of::<T>()]
+    }
+    fn write_types() -> Vec<ResourceTypeId> { Vec::new() }
 }
 
 impl<T: Resource> ResourceSet for PreparedWrite<T> {
@@ -21,4 +25,10 @@ impl<T: Resource> ResourceSet for PreparedWrite<T> {
             .unwrap_or_else(|| panic!("Failed to fetch resource!: {}", std::any::type_name::<T>()));
         PreparedWrite::new(resource.deref_mut() as *mut T)
     }
+    fn read_types() -> Vec<ResourceTypeId> {
+        Vec::new()
+    }
+    fn write_types() -> Vec<ResourceTypeId> {
+        vec![ResourceTypeId::of::<T>()]
+    }
 }
\ No newline at end of file