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 a229ee6..20fa0f8 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/uploadvalidator/BlockedKeywordValidator.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/uploadvalidator/BlockedKeywordValidator.java
@@ -238,6 +238,9 @@
           continue;
         }
       }
+      if (!fileDiffs.containsKey(path)) {
+        continue;
+      }
       checkLineDiffForBlockedKeywords(
           fileDiffs.get(path).edits().stream()
               .map(TaggedEdit::jgitEdit)
diff --git a/src/test/java/com/googlesource/gerrit/plugins/uploadvalidator/BlockedKeywordValidatorTest.java b/src/test/java/com/googlesource/gerrit/plugins/uploadvalidator/BlockedKeywordValidatorTest.java
index c4d0ac4..96d7e90 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/uploadvalidator/BlockedKeywordValidatorTest.java
+++ b/src/test/java/com/googlesource/gerrit/plugins/uploadvalidator/BlockedKeywordValidatorTest.java
@@ -95,6 +95,7 @@
                       Edit.create(0, 0, 0, numberOfLinesInString(fileContent.getValue())),
                       /* dueToRebase = */ false)));
       when(mockDiffs.get(fileContent.getKey())).thenReturn(file);
+      when(mockDiffs.containsKey(fileContent.getKey())).thenReturn(true);
     }
 
     try (RevWalk rw = new RevWalk(repo)) {