diff --git a/crates/caldav/src/calendar/resource.rs b/crates/caldav/src/calendar/resource.rs
index 7ba2e4c..96ae53e 100644
--- a/crates/caldav/src/calendar/resource.rs
+++ b/crates/caldav/src/calendar/resource.rs
@@ -97,7 +97,9 @@ impl Resource for CalendarResource {
     type Error = Error;
     type Principal = User;
 
-    const IS_COLLECTION: bool = true;
+    fn is_collection(&self) -> bool {
+        true
+    }
 
     fn get_resourcetype(&self) -> Resourcetype {
         if self.cal.subscription_url.is_none() {
diff --git a/crates/caldav/src/calendar_object/resource.rs b/crates/caldav/src/calendar_object/resource.rs
index dc46936..1e83d25 100644
--- a/crates/caldav/src/calendar_object/resource.rs
+++ b/crates/caldav/src/calendar_object/resource.rs
@@ -27,7 +27,9 @@ impl Resource for CalendarObjectResource {
     type Error = Error;
     type Principal = User;
 
-    const IS_COLLECTION: bool = false;
+    fn is_collection(&self) -> bool {
+        false
+    }
 
     fn get_resourcetype(&self) -> Resourcetype {
         Resourcetype(&[])
diff --git a/crates/caldav/src/principal/mod.rs b/crates/caldav/src/principal/mod.rs
index 3bae264..e92c4f0 100644
--- a/crates/caldav/src/principal/mod.rs
+++ b/crates/caldav/src/principal/mod.rs
@@ -29,7 +29,9 @@ impl Resource for PrincipalResource {
     type Error = Error;
     type Principal = User;
 
-    const IS_COLLECTION: bool = true;
+    fn is_collection(&self) -> bool {
+        true
+    }
 
     fn get_resourcetype(&self) -> Resourcetype {
         Resourcetype(&[
diff --git a/crates/carddav/src/address_object/resource.rs b/crates/carddav/src/address_object/resource.rs
index 46c53ac..783c4e3 100644
--- a/crates/carddav/src/address_object/resource.rs
+++ b/crates/carddav/src/address_object/resource.rs
@@ -32,7 +32,9 @@ impl Resource for AddressObjectResource {
     type Error = Error;
     type Principal = User;
 
-    const IS_COLLECTION: bool = false;
+    fn is_collection(&self) -> bool {
+        false
+    }
 
     fn get_resourcetype(&self) -> Resourcetype {
         Resourcetype(&[])
diff --git a/crates/carddav/src/addressbook/resource.rs b/crates/carddav/src/addressbook/resource.rs
index c6c13d7..752bddd 100644
--- a/crates/carddav/src/addressbook/resource.rs
+++ b/crates/carddav/src/addressbook/resource.rs
@@ -38,7 +38,9 @@ impl Resource for AddressbookResource {
     type Error = Error;
     type Principal = User;
 
-    const IS_COLLECTION: bool = true;
+    fn is_collection(&self) -> bool {
+        true
+    }
 
     fn get_resourcetype(&self) -> Resourcetype {
         Resourcetype(&[
diff --git a/crates/carddav/src/principal/mod.rs b/crates/carddav/src/principal/mod.rs
index 0e8ec58..27c3955 100644
--- a/crates/carddav/src/principal/mod.rs
+++ b/crates/carddav/src/principal/mod.rs
@@ -29,7 +29,9 @@ impl Resource for PrincipalResource {
     type Error = Error;
     type Principal = User;
 
-    const IS_COLLECTION: bool = true;
+    fn is_collection(&self) -> bool {
+        true
+    }
 
     fn get_resourcetype(&self) -> Resourcetype {
         Resourcetype(&[
diff --git a/crates/dav/src/resource/mod.rs b/crates/dav/src/resource/mod.rs
index 06f130c..4361459 100644
--- a/crates/dav/src/resource/mod.rs
+++ b/crates/dav/src/resource/mod.rs
@@ -37,7 +37,7 @@ pub trait Resource: Clone + Send + 'static {
     type Error: From<crate::Error>;
     type Principal: Principal;
 
-    const IS_COLLECTION: bool;
+    fn is_collection(&self) -> bool;
 
     fn get_resourcetype(&self) -> Resourcetype;
 
@@ -111,7 +111,7 @@ pub trait Resource: Clone + Send + 'static {
     ) -> Result<ResponseElement<Self::Prop>, Self::Error> {
         // Collections have a trailing slash
         let mut path = path.to_string();
-        if Self::IS_COLLECTION && !path.ends_with('/') {
+        if self.is_collection() && !path.ends_with('/') {
             path.push('/');
         }
 
diff --git a/crates/dav/src/resources/root.rs b/crates/dav/src/resources/root.rs
index 9c27858..40b8aa8 100644
--- a/crates/dav/src/resources/root.rs
+++ b/crates/dav/src/resources/root.rs
@@ -24,7 +24,9 @@ impl<PR: Resource, P: Principal> Resource for RootResource<PR, P> {
     type Error = PR::Error;
     type Principal = P;
 
-    const IS_COLLECTION: bool = true;
+    fn is_collection(&self) -> bool {
+        true
+    }
 
     fn get_resourcetype(&self) -> Resourcetype {
         Resourcetype(&[ResourcetypeInner(