diff --git a/sandbox/src/commonMain/kotlin/main.kt b/sandbox/src/commonMain/kotlin/main.kt
index 4237d38..e22cd73 100644
--- a/sandbox/src/commonMain/kotlin/main.kt
+++ b/sandbox/src/commonMain/kotlin/main.kt
@@ -5,15 +5,10 @@ val someStmt = PreparedStatementsCompilationPhantomCache("SELECT * FROM sqlite_m
 
 fun main() {
 	for (i in 0..1000) {
-		DriverManager.getConnection("jdbc:sqlite::memory:").use { connection ->
-			someStmt.preparedStatementForConnection(connection).use { ps ->
-				ps.executeQuery().use { rs ->
-					while (rs.next()) {
-						println(rs.getString(0))
-					}
-				}
-			}
-		}
+		val connection = DriverManager.getConnection("jdbc:sqlite::memory:")
+		val ps = someStmt.preparedStatementForConnection(connection)
+		val rs = ps.executeQuery();
+		connection.close()
 		System.gc()
 	}
 }
\ No newline at end of file
diff --git a/src/jvmMain/java/ru/langrafhomyak/db/jdbc_resources_manager/_PhantomCacheCleanup.java b/src/jvmMain/java/ru/langrafhomyak/db/jdbc_resources_manager/_PhantomCacheCleanup.java
index 184b6ad..27be433 100644
--- a/src/jvmMain/java/ru/langrafhomyak/db/jdbc_resources_manager/_PhantomCacheCleanup.java
+++ b/src/jvmMain/java/ru/langrafhomyak/db/jdbc_resources_manager/_PhantomCacheCleanup.java
@@ -26,7 +26,8 @@ class _PhantomCacheCleanup {
 
 	@NotNull
 	private static Thread _createThread() {
-		if (_PhantomCacheCleanup._isVirtualThreadsSupported() && !System.getProperty(_PhantomCacheCleanup._virtualThreadProperty).equalsIgnoreCase("false")) {
+		final String useVirtualSetting = System.getProperty(_PhantomCacheCleanup._virtualThreadProperty);
+		if (_PhantomCacheCleanup._isVirtualThreadsSupported() && (useVirtualSetting != null && !useVirtualSetting.equalsIgnoreCase("false"))) {
 			return _PhantomCacheCleanup._startVirtualThread();
 		} else {
 			return _PhantomCacheCleanup._startVirtualThread();
@@ -58,7 +59,7 @@ class _PhantomCacheCleanup {
 
 	@NotNull
 	private static Thread _startVirtualThread() {
-		final var b = Thread.ofVirtual();
+		final Thread.Builder.OfVirtual b = Thread.ofVirtual();
 		b.name(_PhantomCacheCleanup._threadName);
 		b.inheritInheritableThreadLocals(false);
 		return b.start(new CleanupRoutine());
@@ -72,7 +73,10 @@ class _PhantomCacheCleanup {
 				// (Thread.currentThread() as? InnocuousThread)?.eraseThreadLocals()
 
 				try {
-					((CleanablePhantomReference<?>) _PhantomCacheCleanup._referenceQueue.remove(60 * 60)).cleanup();
+					final CleanablePhantomReference<?> cleanableRef = ((CleanablePhantomReference<?>) _PhantomCacheCleanup._referenceQueue.remove(60 * 60));
+					if (cleanableRef == null)
+						continue;
+					cleanableRef.cleanup();
 				} /* catch (_: LinkageError) {
 					return
 				} */ catch (InterruptedException e) {