diff --git a/mutation_partition.hh b/mutation_partition.hh
index e9db79c9ed..5b12345ba7 100644
--- a/mutation_partition.hh
+++ b/mutation_partition.hh
@@ -826,6 +826,7 @@ public:
 
     void apply(tombstone deleted_at) {
         _deleted_at.apply(deleted_at);
+        maybe_shadow();
     }
 
     void apply(shadowable_tombstone deleted_at) {
diff --git a/test/boost/mutation_test.cc b/test/boost/mutation_test.cc
index e7b47b8762..30ee4e2112 100644
--- a/test/boost/mutation_test.cc
+++ b/test/boost/mutation_test.cc
@@ -1852,6 +1852,29 @@ SEASTAR_TEST_CASE(test_continuity_merging_of_complete_mutations) {
     return make_ready_future<>();
 }
 
+SEASTAR_TEST_CASE(test_commutativity_and_associativity) {
+    random_mutation_generator gen(random_mutation_generator::generate_counters::no);
+    gen.set_key_cardinality(7);
+
+    for (int i = 0; i < 10; ++i) {
+        mutation m1 = gen();
+        m1.partition().make_fully_continuous();
+        mutation m2 = gen();
+        m2.partition().make_fully_continuous();
+        mutation m3 = gen();
+        m3.partition().make_fully_continuous();
+
+        assert_that(m1 + m2 + m3)
+            .is_equal_to(m1 + m3 + m2)
+            .is_equal_to(m2 + m1 + m3)
+            .is_equal_to(m2 + m3 + m1)
+            .is_equal_to(m3 + m1 + m2)
+            .is_equal_to(m3 + m2 + m1);
+    }
+
+    return make_ready_future<>();
+}
+
 SEASTAR_TEST_CASE(test_continuity_merging) {
     return seastar::async([] {
         simple_schema table;
diff --git a/test/lib/mutation_source_test.cc b/test/lib/mutation_source_test.cc
index 1b5c4d6e3e..bc6b9bc9eb 100644
--- a/test/lib/mutation_source_test.cc
+++ b/test/lib/mutation_source_test.cc
@@ -2247,6 +2247,11 @@ public:
             if (_not_dummy_dist(_gen)) {
                 deletable_row& row = m.partition().clustered_row(*_schema, ckey, is_dummy::no, continuous);
                 row.apply(random_row_marker());
+                if (!row.marker().is_missing() && !row.marker().is_live()) {
+                    // Mutations are not associative if dead marker is not matched with a dead row
+                    // due to shadowable tombstone merging rules. See #11307.
+                    row.apply(tombstone(row.marker().timestamp(), row.marker().deletion_time()));
+                }
                 if (_bool_dist(_gen)) {
                     set_random_cells(row.cells(), column_kind::regular_column);
                 } else {