diff --git a/src/shared/image-policy.c b/src/shared/image-policy.c
index 1fb24138fb..e08fbba966 100644
--- a/src/shared/image-policy.c
+++ b/src/shared/image-policy.c
@@ -774,6 +774,56 @@ int image_policy_intersect(const ImagePolicy *a, const ImagePolicy *b, ImagePoli
         return 0;
 }
 
+int image_policy_ignore_designators(const ImagePolicy *p, const PartitionDesignator table[], size_t n_table, ImagePolicy **ret) {
+        assert(p);
+        assert(table || n_table == 0);
+        assert(ret);
+
+        /* Patches the specified image policy, replacing the policy for the specified designators by an
+         * "ignore" policy. Returns a patched copy. This is useful in context where only some of the
+         * available partitions shall be mounted, and hence the policy for the others really doesn't
+         * matter. */
+
+        _cleanup_(image_policy_freep) ImagePolicy *np = image_policy_new(_PARTITION_DESIGNATOR_MAX);
+        if (!np)
+                return -ENOMEM;
+
+        FOREACH_ARRAY(t, table, n_table) {
+                assert(*t >= 0);
+                assert(*t < _PARTITION_DESIGNATOR_MAX);
+
+                if (image_policy_bsearch(np, *t))
+                        continue;
+
+                /* Insert an ignore policy for this entry, and sort it to the right place, so that image_policy_bsearch() can work */
+                np->policies[np->n_policies++] = (PartitionPolicy) {
+                        .designator = *t,
+                        .flags = PARTITION_POLICY_IGNORE,
+                };
+                typesafe_qsort(np->policies, np->n_policies, partition_policy_compare);
+        }
+
+        FOREACH_ARRAY(i, p->policies, p->n_policies) {
+
+                if (image_policy_bsearch(np, i->designator))
+                        continue;
+
+                /* Copy the policy entry from the old image policy, and sort it to the right place, so that image_policy_bsearch() can work */
+                np->policies[np->n_policies++] = *i;
+                typesafe_qsort(np->policies, np->n_policies, partition_policy_compare);
+        }
+
+        np->default_flags = p->default_flags;
+
+        /* Return unused space to libc */
+        ImagePolicy *t = realloc(np, offsetof(ImagePolicy, policies) + sizeof(PartitionPolicy) * np->n_policies);
+        if (t)
+                np = t;
+
+        *ret = TAKE_PTR(np);
+        return 0;
+}
+
 const ImagePolicy image_policy_allow = {
         /* Allow policy */
         .n_policies = 0,
diff --git a/src/shared/image-policy.h b/src/shared/image-policy.h
index a1a6afa345..f61f55fd60 100644
--- a/src/shared/image-policy.h
+++ b/src/shared/image-policy.h
@@ -106,3 +106,5 @@ DEFINE_TRIVIAL_CLEANUP_FUNC(ImagePolicy*, image_policy_free);
 
 CONFIG_PARSER_PROTOTYPE(config_parse_image_policy);
 int parse_image_policy_argument(const char *s, ImagePolicy **policy);
+
+int image_policy_ignore_designators(const ImagePolicy *p, const PartitionDesignator table[], size_t n_table, ImagePolicy **ret);
diff --git a/src/test/test-image-policy.c b/src/test/test-image-policy.c
index 12fc10acf0..7d29e3d12e 100644
--- a/src/test/test-image-policy.c
+++ b/src/test/test-image-policy.c
@@ -162,4 +162,31 @@ TEST(image_policy_intersect) {
         test_policy_intersect_one("root=open", "=verity+ignore", "root=verity+ignore:=ignore");
 }
 
+static void test_policy_ignore_designators_one(const char *a, const PartitionDesignator array[], size_t n, const char *b) {
+        _cleanup_(image_policy_freep) ImagePolicy *x = NULL, *y = NULL, *t = NULL;
+
+        ASSERT_OK(image_policy_from_string(a, &x));
+        ASSERT_OK(image_policy_from_string(b, &y));
+
+        _cleanup_free_ char *s1 = NULL, *s2 = NULL, *s3 = NULL;
+        ASSERT_OK(image_policy_to_string(x, true, &s1));
+        ASSERT_OK(image_policy_to_string(y, true, &s2));
+
+        ASSERT_OK(image_policy_ignore_designators(x, array, n, &t));
+
+        ASSERT_OK(image_policy_to_string(t, true, &s3));
+
+        log_info("%s → %s vs. %s", s1, s2, s3);
+
+        ASSERT_TRUE(image_policy_equivalent(t, y));
+}
+
+TEST(image_policy_ignore_designators) {
+        test_policy_ignore_designators_one("-", NULL, 0, "-");
+        test_policy_ignore_designators_one("-", ((const PartitionDesignator[]) { PARTITION_ROOT }), 1, "-");
+        test_policy_ignore_designators_one("*", ((const PartitionDesignator[]) { PARTITION_ROOT }), 1, "root=ignore:=open");
+        test_policy_ignore_designators_one("*", ((const PartitionDesignator[]) { PARTITION_ROOT, PARTITION_USR }), 2, "root=ignore:usr=ignore:=open");
+        test_policy_ignore_designators_one("~", ((const PartitionDesignator[]) { PARTITION_VAR, PARTITION_ESP, PARTITION_VAR }), 2, "var=ignore:esp=ignore:=absent");
+}
+
 DEFINE_TEST_MAIN(LOG_INFO);