diff --git a/repos/base/src/lib/base/slab.cc b/repos/base/src/lib/base/slab.cc
index f790b911d4..cf088b7e2d 100644
--- a/repos/base/src/lib/base/slab.cc
+++ b/repos/base/src/lib/base/slab.cc
@@ -438,7 +438,8 @@ void Slab::_free(void *addr)
 	_curr_sb = █
 	while (_total_avail > 2*_entries_per_block
 	 && _num_blocks > 1
-	 && _curr_sb->avail() == _entries_per_block) {
+	 && _curr_sb->avail() == _entries_per_block
+	 && _backing_store) {
 		_free_curr_sb();
 	}
 }