diff --git a/base-nova/src/core/core_rm_session.cc b/base-nova/src/core/core_rm_session.cc
index d1e2165f40..47d4e86758 100644
--- a/base-nova/src/core/core_rm_session.cc
+++ b/base-nova/src/core/core_rm_session.cc
@@ -36,9 +36,6 @@ Core_rm_session::attach(Dataspace_capability ds_cap, size_t size,
 	if (!ds)
 		throw Invalid_dataspace();
 
-	if (size == 0)
-		size = ds->size();
-
 	if (use_local_addr) {
 		PERR("Parameter 'use_local_addr' not supported within core");
 		return 0UL;
diff --git a/base-nova/src/core/include/core_rm_session.h b/base-nova/src/core/include/core_rm_session.h
index d3a9780555..a6d1937216 100644
--- a/base-nova/src/core/include/core_rm_session.h
+++ b/base-nova/src/core/include/core_rm_session.h
@@ -37,7 +37,15 @@ namespace Genode {
 			                  Local_addr local_addr = 0,
 			                  bool executable = false);
 
-			void detach(Local_addr) { }
+			void detach(Local_addr)
+			{
+				/*
+				 * The core-local mapping gets established in
+				 * 'Ram_session_component::_clear_ds()' and reverted in
+				 * 'Ram_session_component::_revoke_ram_ds(), so there's
+				 * nothing to do here.
+				 */
+			}
 
 			Pager_capability add_client(Thread_capability thread) {
 				return Pager_capability(); }
diff --git a/base-nova/src/core/ram_session_support.cc b/base-nova/src/core/ram_session_support.cc
index 031be90236..2f5bbc698a 100644
--- a/base-nova/src/core/ram_session_support.cc
+++ b/base-nova/src/core/ram_session_support.cc
@@ -29,7 +29,20 @@ enum { verbose_ram_ds = false };
 using namespace Genode;
 
 void Ram_session_component::_export_ram_ds(Dataspace_component *ds) { }
-void Ram_session_component::_revoke_ram_ds(Dataspace_component *ds) { }
+
+void Ram_session_component::_revoke_ram_ds(Dataspace_component *ds)
+{
+	size_t page_rounded_size = (ds->size() + get_page_size() - 1) & get_page_mask();
+
+	unmap_local((Nova::Utcb *)Thread_base::myself()->utcb(),
+	            ds->core_local_addr(),
+	            page_rounded_size >> get_page_size_log2());
+
+	platform()->region_alloc()->free((void*)ds->core_local_addr(),
+	                                 page_rounded_size);
+
+	ds->assign_core_local_addr(0);
+}
 
 void Ram_session_component::_clear_ds(Dataspace_component *ds)
 {