diff --git a/src/main/java/com/googlesource/gerrit/plugins/uploadvalidator/BlockedKeywordValidator.java b/src/main/java/com/googlesource/gerrit/plugins/uploadvalidator/BlockedKeywordValidator.java
index ef66c33..64ce6ab 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/uploadvalidator/BlockedKeywordValidator.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/uploadvalidator/BlockedKeywordValidator.java
@@ -24,6 +24,7 @@
 import com.google.common.collect.ImmutableListMultimap;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.Iterables;
+import com.google.common.flogger.FluentLogger;
 import com.google.gerrit.entities.Patch;
 import com.google.gerrit.entities.Project;
 import com.google.gerrit.entities.Project.NameKey;
@@ -85,6 +86,8 @@
  * validator classes to run its list of blocked keywords against commit content and comments.
  */
 public class BlockedKeywordValidator implements CommitValidationListener, CommentValidator {
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
+
   // These keys are used for turning on specific validation elements.
   // i.e. enableSkipValidation = blockedKeyword will enabled skipRef and skipGroup checks
   // i.e. disabledValidation = blockedKeywordComments will disable the comment blocked keyword check
@@ -176,10 +179,7 @@
           }
         }
       }
-    } catch (NoSuchProjectException
-        | IOException
-        | ExecutionException
-        | PatchListNotAvailableException e) {
+    } catch (NoSuchProjectException | IOException | ExecutionException e) {
       throw new CommitValidationException("failed to check on blocked keywords", e);
     }
     return Collections.emptyList();
@@ -221,13 +221,25 @@
       RevWalk revWalk,
       ImmutableCollection<Pattern> blockedKeywordPatterns,
       PluginConfig cfg)
-      throws IOException, ExecutionException, PatchListNotAvailableException {
+      throws IOException, ExecutionException {
     List<CommitValidationMessage> messages = new LinkedList<>();
     checkCommitMessageForBlockedKeywords(blockedKeywordPatterns, messages, c.getFullMessage());
     Map<String, ObjectId> content = CommitUtils.getChangedContent(repo, c, revWalk);
-    PatchList patchList =
-        patchListCache.get(
-            PatchListKey.againstDefaultBase(c, DiffPreferencesInfo.Whitespace.IGNORE_NONE), project);
+    Optional<PatchList> patchList;
+    try {
+      patchList =
+          Optional.of(
+              patchListCache.get(
+                  PatchListKey.againstDefaultBase(c, DiffPreferencesInfo.Whitespace.IGNORE_NONE),
+                  project));
+    } catch (PatchListNotAvailableException e) {
+      // TODO(hiesel): Make changes to Gerrit core to always get a diff here. This entails figuring
+      // out Git object visibility between unflushed ObjectInserters and ObjectReaders created from
+      // the repo.
+      logger.atInfo().withCause(e).log("unable to load patch set");
+      patchList = Optional.empty();
+    }
+
     for (String path : content.keySet()) {
       ObjectLoader ol = revWalk.getObjectReader().open(content.get(path));
       try (InputStream in = ol.openStream()) {
@@ -235,8 +247,12 @@
           continue;
         }
       }
-      checkLineDiffForBlockedKeywords(
-          patchList.get(path).getEdits(), blockedKeywordPatterns, messages, path, ol);
+      if (patchList.isPresent()) {
+        checkLineDiffForBlockedKeywords(
+            patchList.get().get(path).getEdits(), blockedKeywordPatterns, messages, path, ol);
+      } else {
+        checkEntireFileForBlockedKeywords(blockedKeywordPatterns, messages, path, ol);
+      }
     }
     return messages;
   }
@@ -288,6 +304,22 @@
     }
   }
 
+  private static void checkEntireFileForBlockedKeywords(
+      ImmutableCollection<Pattern> blockedKeywordPatterns,
+      List<CommitValidationMessage> messages,
+      String path,
+      ObjectLoader ol)
+      throws IOException {
+    try (BufferedReader br =
+        new BufferedReader(new InputStreamReader(ol.openStream(), StandardCharsets.UTF_8))) {
+      int line = 1;
+      for (String l = br.readLine(); l != null; l = br.readLine()) {
+        checkLineForBlockedKeywords(blockedKeywordPatterns, messages, path, line, l);
+        line++;
+      }
+    }
+  }
+
   private static List<String> findBlockedKeywordsInString(
       ImmutableCollection<Pattern> blockedKeywordPatterns, String text) {
     List<String> found = new ArrayList<>();
diff --git a/src/test/java/com/googlesource/gerrit/plugins/uploadvalidator/UploadValidatorIT.java b/src/test/java/com/googlesource/gerrit/plugins/uploadvalidator/UploadValidatorIT.java
index bee5418..bd5f8f3 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/uploadvalidator/UploadValidatorIT.java
+++ b/src/test/java/com/googlesource/gerrit/plugins/uploadvalidator/UploadValidatorIT.java
@@ -31,7 +31,11 @@
 import com.google.gerrit.extensions.api.changes.DraftInput;
 import com.google.gerrit.extensions.api.changes.ReviewInput;
 import com.google.gerrit.extensions.api.changes.ReviewInput.DraftHandling;
+import com.google.gerrit.extensions.client.ChangeStatus;
+import com.google.gerrit.extensions.common.ChangeInput;
+import com.google.gerrit.extensions.common.MergeInput;
 import com.google.gerrit.extensions.restapi.BadRequestException;
+import com.google.gerrit.extensions.restapi.ResourceConflictException;
 import com.google.gerrit.server.group.SystemGroupBackend;
 import com.google.inject.Inject;
 import org.eclipse.jgit.internal.storage.dfs.InMemoryRepository;
@@ -367,4 +371,62 @@
         .to("refs/heads/master")
         .assertOkStatus();
   }
+
+  @Test
+  public void createChangeSucceedsWhenKeywordDoesNotExistInFileAndDiff() throws Exception {
+    RevCommit head = getHead(testRepo.getRepository(), "HEAD");
+    pushConfig(
+        Joiner.on("\n").join("[plugin \"uploadvalidator\"]", "    blockedKeywordPattern = secr3t"));
+    pushFactory
+        .create(admin.newIdent(), clone, "Subject", "file.txt", "" + "blah \n")
+        .to("refs/heads/master")
+        .assertOkStatus();
+    clone.reset(head);
+    pushFactory
+        .create(admin.newIdent(), clone, "Subject", "foo.txt", "" + "blah \n")
+        .to("refs/heads/stable")
+        .assertOkStatus();
+    // Create a change that merges the other branch into master. This defaults back to
+    // full-file validation. If it doesn't, the create change call below would fail with
+    // a MissingObjectException.
+    ChangeInput changeInput = new ChangeInput();
+    changeInput.project = project.get();
+    changeInput.branch = "master";
+    changeInput.subject = "A change";
+    changeInput.status = ChangeStatus.NEW;
+    MergeInput mergeInput = new MergeInput();
+    mergeInput.source = gApi.projects().name(project.get()).branch("stable").get().revision;
+    changeInput.merge = mergeInput;
+    gApi.changes().create(changeInput);
+  }
+
+  @Test
+  public void createChangeWithKeywordInMessageFails() throws Exception {
+    RevCommit head = getHead(testRepo.getRepository(), "HEAD");
+    pushConfig(
+        Joiner.on("\n").join("[plugin \"uploadvalidator\"]", "    blockedKeywordPattern = secr3t"));
+    pushFactory
+        .create(admin.newIdent(), clone, "Subject", "file.txt", "" + "blah \n")
+        .to("refs/heads/master")
+        .assertOkStatus();
+    clone.reset(head);
+    pushFactory
+        .create(admin.newIdent(), clone, "Subject", "foo.txt", "" + "blah \n")
+        .to("refs/heads/stable")
+        .assertOkStatus();
+    // Create a change that merges the other branch into master. This defaults back to
+    // full-file validation. If it doesn't, the create change call below would fail with
+    // a MissingObjectException.
+    ChangeInput changeInput = new ChangeInput();
+    changeInput.project = project.get();
+    changeInput.branch = "master";
+    changeInput.subject = "A secr3t change";
+    changeInput.status = ChangeStatus.NEW;
+    MergeInput mergeInput = new MergeInput();
+    mergeInput.source = gApi.projects().name(project.get()).branch("stable").get().revision;
+    changeInput.merge = mergeInput;
+    ResourceConflictException e =
+        assertThrows(ResourceConflictException.class, () -> gApi.changes().create(changeInput));
+    assertThat(e).hasMessageThat().contains("blocked keyword(s) found");
+  }
 }