diff --git a/sdk/core/switcher/entry.S b/sdk/core/switcher/entry.S
index 6e6bcfc..3a400cf 100644
--- a/sdk/core/switcher/entry.S
+++ b/sdk/core/switcher/entry.S
@@ -218,7 +218,7 @@
 
 /**
  * Clear the hazard pointers associated with this thread.  (See
- * include/stdlib.h:/heap_claim_fast, and its implementation in
+ * include/stdlib.h:/heap_claim_ephemeral, and its implementation in
  * lib/compartment_helpers/claim_fast.cc for more about hazard pointers.)  We
  * don't care about leaks here (they're store-only from anywhere except the
  * allocator), so just write a 32-bit zero over half of each one to clobber the
diff --git a/sdk/include/locks.h b/sdk/include/locks.h
index c33474a..ef8a718 100644
--- a/sdk/include/locks.h
+++ b/sdk/include/locks.h
@@ -95,7 +95,7 @@
  *
  * Note: if the object is deallocated while trying to acquire the lock, then
  * this will fault.  In many cases, this is called at a compartment boundary
- * and so this is fine.  If it is not acceptable, use `heap_claim_fast` to
+ * and so this is fine.  If it is not acceptable, use `heap_claim_ephemeral` to
  * ensure that the object remains live until after the call.
  */
 int __cheri_libcall
diff --git a/sdk/include/platform/sunburst/v0.2/platform-ethernet.hh b/sdk/include/platform/sunburst/v0.2/platform-ethernet.hh
index c33ddba..f4bf3e3 100644
--- a/sdk/include/platform/sunburst/v0.2/platform-ethernet.hh
+++ b/sdk/include/platform/sunburst/v0.2/platform-ethernet.hh
@@ -751,7 +751,7 @@
 		// does not check the pointer which is coming from external
 		// untrusted components.
 		Timeout t{10};
-		if ((heap_claim_fast(&t, buffer) < 0) ||
+		if ((heap_claim_ephemeral(&t, buffer) < 0) ||
 		    (!CHERI::check_pointer<CHERI::PermissionSet{
 		       CHERI::Permission::Load}>(buffer, length)))
 		{
diff --git a/sdk/lib/compartment_helpers/README.md b/sdk/lib/compartment_helpers/README.md
index 90857ae..6343379 100644
--- a/sdk/lib/compartment_helpers/README.md
+++ b/sdk/lib/compartment_helpers/README.md
@@ -3,5 +3,5 @@
 
 This library includes functions that help securing compartment boundaries.
 
-- [`claim_fast.cc`] contains the `heap_claim_fast` function.
+- [`claim_fast.cc`] contains the `heap_claim_ephemeral` function.
 - [`check_pointer.cc`] contains the `check_pointer` function.