diff --git a/payload_generator/payload_file.cc b/payload_generator/payload_file.cc
index de81a39..2f95b21 100644
--- a/payload_generator/payload_file.cc
+++ b/payload_generator/payload_file.cc
@@ -138,6 +138,7 @@
           partition->set_postinstall_path(part.postinstall.path);
         if (!part.postinstall.filesystem_type.empty())
           partition->set_filesystem_type(part.postinstall.filesystem_type);
+        partition->set_postinstall_optional(part.postinstall.optional);
       }
       for (const AnnotatedOperation& aop : part.aops) {
         *partition->add_operations() = aop.op;
diff --git a/payload_generator/payload_generation_config.cc b/payload_generator/payload_generation_config.cc
index c705f60..38a72a9 100644
--- a/payload_generator/payload_generation_config.cc
+++ b/payload_generator/payload_generation_config.cc
@@ -28,7 +28,7 @@
 namespace chromeos_update_engine {
 
 bool PostInstallConfig::IsEmpty() const {
-  return run == false && path.empty() && filesystem_type.empty();
+  return !run && path.empty() && filesystem_type.empty() && !optional;
 }
 
 bool PartitionConfig::ValidateExists() const {
@@ -90,6 +90,8 @@
     store.GetString("POSTINSTALL_PATH_" + part.name, &part.postinstall.path);
     store.GetString("FILESYSTEM_TYPE_" + part.name,
                     &part.postinstall.filesystem_type);
+    store.GetBoolean("POSTINSTALL_OPTIONAL_" + part.name,
+                     &part.postinstall.optional);
   }
   if (!found_postinstall) {
     LOG(ERROR) << "No valid postinstall config found.";
diff --git a/payload_generator/payload_generation_config.h b/payload_generator/payload_generation_config.h
index 2601821..373c7cd 100644
--- a/payload_generator/payload_generation_config.h
+++ b/payload_generator/payload_generation_config.h
@@ -46,6 +46,9 @@
   // The filesystem type used to mount the partition in order to run the
   // post-install program.
   std::string filesystem_type;
+
+  // Whether this postinstall script should be ignored if it fails.
+  bool optional = false;
 };
 
 struct PartitionConfig {
diff --git a/payload_generator/payload_generation_config_unittest.cc b/payload_generator/payload_generation_config_unittest.cc
index 122d94a..3545056 100644
--- a/payload_generator/payload_generation_config_unittest.cc
+++ b/payload_generator/payload_generation_config_unittest.cc
@@ -29,12 +29,14 @@
   EXPECT_TRUE(
       store.LoadFromString("RUN_POSTINSTALL_root=true\n"
                            "POSTINSTALL_PATH_root=postinstall\n"
-                           "FILESYSTEM_TYPE_root=ext4"));
+                           "FILESYSTEM_TYPE_root=ext4\n"
+                           "POSTINSTALL_OPTIONAL_root=true"));
   EXPECT_TRUE(image_config.LoadPostInstallConfig(store));
   EXPECT_FALSE(image_config.partitions[0].postinstall.IsEmpty());
   EXPECT_EQ(true, image_config.partitions[0].postinstall.run);
   EXPECT_EQ("postinstall", image_config.partitions[0].postinstall.path);
   EXPECT_EQ("ext4", image_config.partitions[0].postinstall.filesystem_type);
+  EXPECT_TRUE(image_config.partitions[0].postinstall.optional);
 }
 
 TEST_F(PayloadGenerationConfigTest, LoadPostInstallConfigNameMismatchTest) {