diff --git a/bindings/java/src/org/sleuthkit/datamodel/EncodedFileOutputStream.java b/bindings/java/src/org/sleuthkit/datamodel/EncodedFileOutputStream.java
index 7c0183e1dd..3fcf544d35 100644
--- a/bindings/java/src/org/sleuthkit/datamodel/EncodedFileOutputStream.java
+++ b/bindings/java/src/org/sleuthkit/datamodel/EncodedFileOutputStream.java
@@ -71,13 +71,13 @@ private void writeHeader() throws IOException {
 	}
 
 	@Override
-	public void write(int b) throws IOException {
+	public synchronized void write(int b) throws IOException {
 		super.write((int) EncodedFileUtil.encodeByte((byte) b, type));
 		encodedDataLength++;
 	}
 
 	@Override
-	public void write(byte[] b,
+	public synchronized void write(byte[] b,
 			int off,
 			int len)
 			throws IOException {
diff --git a/bindings/java/src/org/sleuthkit/datamodel/OsAccountManager.java b/bindings/java/src/org/sleuthkit/datamodel/OsAccountManager.java
index 35fb27bacc..9566ea174e 100755
--- a/bindings/java/src/org/sleuthkit/datamodel/OsAccountManager.java
+++ b/bindings/java/src/org/sleuthkit/datamodel/OsAccountManager.java
@@ -1386,6 +1386,7 @@ public Optional<OsAccount> getLocalLinuxOsAccount(String uid, String loginName,
 		}
 	}	
 	
+	private final Object osAccountLockObj = new Object();
 	/**
 	 * Adds a rows to the tsk_os_account_attributes table for the given set of
 	 * attribute.
@@ -1397,7 +1398,7 @@ public Optional<OsAccount> getLocalLinuxOsAccount(String uid, String loginName,
 	 */
 	public void addExtendedOsAccountAttributes(OsAccount account, List<OsAccountAttribute> accountAttributes) throws TskCoreException {
 
-		synchronized (account) {  // synchronized to prevent multiple threads trying to add osAccount attributes concurrently to the same osAccount.
+		synchronized (osAccountLockObj) {  // synchronized to prevent multiple threads trying to add osAccount attributes concurrently to the same osAccount.
 			db.acquireSingleUserCaseWriteLock();
 
 			try (CaseDbConnection connection = db.getConnection()) {
diff --git a/bindings/java/test/org/sleuthkit/datamodel/HashDbTest.java b/bindings/java/test/org/sleuthkit/datamodel/HashDbTest.java
index 37868f875d..e79c6d4c15 100644
--- a/bindings/java/test/org/sleuthkit/datamodel/HashDbTest.java
+++ b/bindings/java/test/org/sleuthkit/datamodel/HashDbTest.java
@@ -61,7 +61,6 @@ public static Collection<Object[]> testImageData() {
 
 		for (Object imagePaths : DataModelTestSuite.getImagePaths()) {
 			data.add(new Object[]{imagePaths});
-			break;
 		}
 		return data;
 	}