diff --git a/org.eclipse.jdt.compiler.tool.tests/src/org/eclipse/jdt/compiler/tool/tests/AbstractCompilerToolTest.java b/org.eclipse.jdt.compiler.tool.tests/src/org/eclipse/jdt/compiler/tool/tests/AbstractCompilerToolTest.java
index cd6cbfe..cb26233 100644
--- a/org.eclipse.jdt.compiler.tool.tests/src/org/eclipse/jdt/compiler/tool/tests/AbstractCompilerToolTest.java
+++ b/org.eclipse.jdt.compiler.tool.tests/src/org/eclipse/jdt/compiler/tool/tests/AbstractCompilerToolTest.java
@@ -12,6 +12,7 @@
 package org.eclipse.jdt.compiler.tool.tests;
 
 import java.io.File;
+import java.io.IOException;
 import java.io.PrintWriter;
 import java.util.ArrayList;
 import java.util.List;
@@ -98,16 +99,24 @@
 		if (manager == null) {
 			manager = COMPILER.getStandardFileManager(null, null, null); // will pick defaults up
 		}
-		List<File> files = new ArrayList<File>();
-		String[] fileNames = arguments.fileNames;
-		for (int i = 0, l = fileNames.length; i < l; i++) {
-			if (fileNames[i].startsWith(OUTPUT_DIR)) {
-				files.add(new File(fileNames[i]));
-			} else {
-				files.add(new File(OUTPUT_DIR + File.separator + fileNames[i]));
+		try {
+			List<File> files = new ArrayList<File>();
+			String[] fileNames = arguments.fileNames;
+			for (int i = 0, l = fileNames.length; i < l; i++) {
+				if (fileNames[i].startsWith(OUTPUT_DIR)) {
+					files.add(new File(fileNames[i]));
+				} else {
+					files.add(new File(OUTPUT_DIR + File.separator + fileNames[i]));
+				}
 			}
-		}
-		CompilationTask task = COMPILER.getTask(out, arguments.standardJavaFileManager /* carry the null over */, new CompilerInvocationDiagnosticListener(err), arguments.options, null, manager.getJavaFileObjectsFromFiles(files));
-		return task.call();
+			CompilationTask task = COMPILER.getTask(out, arguments.standardJavaFileManager /* carry the null over */, new CompilerInvocationDiagnosticListener(err), arguments.options, null, manager.getJavaFileObjectsFromFiles(files));
+			return task.call();
+		} finally {
+			try {
+				manager.close();
+			} catch (IOException e) {
+				// nop
+			}
+		}		
 	}
 }
diff --git a/org.eclipse.jdt.compiler.tool.tests/src/org/eclipse/jdt/compiler/tool/tests/CompilerInvocationTests.java b/org.eclipse.jdt.compiler.tool.tests/src/org/eclipse/jdt/compiler/tool/tests/CompilerInvocationTests.java
index 60be95f..09a1689 100644
--- a/org.eclipse.jdt.compiler.tool.tests/src/org/eclipse/jdt/compiler/tool/tests/CompilerInvocationTests.java
+++ b/org.eclipse.jdt.compiler.tool.tests/src/org/eclipse/jdt/compiler/tool/tests/CompilerInvocationTests.java
@@ -502,7 +502,9 @@
 		remaining = remainingAsList.iterator();
 		assertTrue("does not support -d option", javacStandardJavaFileManager.handleOption("-d", remaining));
 		assertEquals("unexpected consumption rate", "remainder", remaining.next());
+		javacStandardJavaFileManager.close();
 	}
+	ecjStandardJavaFileManager.close();
 }
 // https://bugs.eclipse.org/bugs/show_bug.cgi?id=226918
 // options consumption - check consumption rate on supported zero-args options
@@ -525,6 +527,7 @@
 			assertEquals("unexpected consumption rate", REMAINDER, remaining.next());
 		}
 	}
+	ecjStandardJavaFileManager.close();
 }
 // https://bugs.eclipse.org/bugs/show_bug.cgi?id=226918
 // options consumption - check consumption rate on supported one-arg options
@@ -540,6 +543,7 @@
 			assertEquals("unexpected consumption rate", REMAINDER, remaining.next());
 		}
 	}
+	ecjStandardJavaFileManager.close();
 }
 // tests #10-11 show that ecj throws a RuntimeException when encountering a wrong
 // encoding in its parameters, while the default compiler swallows it silently
diff --git a/org.eclipse.jdt.compiler.tool.tests/src/org/eclipse/jdt/compiler/tool/tests/CompilerToolTests.java b/org.eclipse.jdt.compiler.tool.tests/src/org/eclipse/jdt/compiler/tool/tests/CompilerToolTests.java
index 84e2c1f..bf44e40 100644
--- a/org.eclipse.jdt.compiler.tool.tests/src/org/eclipse/jdt/compiler/tool/tests/CompilerToolTests.java
+++ b/org.eclipse.jdt.compiler.tool.tests/src/org/eclipse/jdt/compiler/tool/tests/CompilerToolTests.java
@@ -19,6 +19,7 @@
 import java.io.StringWriter;
 import java.nio.charset.Charset;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.List;
@@ -604,7 +605,7 @@
 		assertTrue("delete failed", inputFile.delete());
 	}
 
-	public void testCompilerOneClassWithEclipseCompiler4() {
+	public void testCompilerOneClassWithEclipseCompiler4() throws IOException {
 		JavaCompiler systemCompiler = ToolProvider.getSystemJavaCompiler();
 		if (systemCompiler == null) {
 			System.out.println("No system java compiler available");
@@ -653,6 +654,7 @@
 		}
 		// check that the .class file exist for X
 		assertTrue("delete failed", inputFile.delete());
+		manager.close();
 	}
 
 	public void testCompilerOneClassWithEclipseCompiler5() {
@@ -869,6 +871,7 @@
 				builder.append(name.substring(lastIndexOf + 1));
 			}
 			assertEquals("Wrong contents", "X.java", String.valueOf(builder));
+			fileManager.close();
 		} catch (IOException e) {
 			e.printStackTrace();
 		}
@@ -934,15 +937,17 @@
 			Iterable<? extends JavaFileObject> compilationUnits = fileManager.list(sourceLoc, "", fileTypes, true);
 	
 			Iterator<? extends JavaFileObject> it = compilationUnits.iterator();
-			StringBuilder builder = new StringBuilder();
+			List<String> names = new ArrayList<String>();
 			while (it.hasNext()) {
 				JavaFileObject next = it.next();
 				String name = next.getName();
 				name = name.replace('\\', '/');
 				int lastIndexOf = name.lastIndexOf('/');
-				builder.append(name.substring(lastIndexOf + 1));
+				names.add(name.substring(lastIndexOf + 1));
 			}
-			assertEquals("Wrong contents", "X2.javaX.java", String.valueOf(builder));
+			Collections.sort(names);
+			assertEquals("Wrong contents", "[X.java, X2.java]", names.toString());
+			fileManager.close();
 		} catch (IOException e) {
 			e.printStackTrace();
 		}