diff --git a/org.eclipse.lsp4xml/src/test/java/org/eclipse/lsp4xml/extensions/contentmodel/BaseFileTempTest.java b/org.eclipse.lsp4xml/src/test/java/org/eclipse/lsp4xml/extensions/contentmodel/BaseFileTempTest.java
index 93c5543714..7ec566d648 100644
--- a/org.eclipse.lsp4xml/src/test/java/org/eclipse/lsp4xml/extensions/contentmodel/BaseFileTempTest.java
+++ b/org.eclipse.lsp4xml/src/test/java/org/eclipse/lsp4xml/extensions/contentmodel/BaseFileTempTest.java
@@ -4,20 +4,21 @@
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.net.URI;
+import java.net.URISyntaxException;
+import java.nio.file.Files;
+import java.nio.file.Path;
 import java.nio.file.Paths;
 
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
 
-import com.google.common.base.Charsets;
-import com.google.common.io.Files;
 import com.google.common.io.MoreFiles;
 import com.google.common.io.RecursiveDeleteOption;
 
 public class BaseFileTempTest {
 
-	protected static final String tempDirPath = "target/temp/";
-	protected static final URI tempDirUri = Paths.get(tempDirPath).toAbsolutePath().toUri();
+	private static final Path tempDirPath = Paths.get("target/temp/");
+	protected static final URI tempDirUri = tempDirPath.toAbsolutePath().toUri();
 
 	@BeforeClass
 	public static void setup() throws FileNotFoundException, IOException {
@@ -42,7 +43,26 @@ private static void createTempDir() {
 		tempDir.mkdir();
 	}
 
-	protected static void createFile(String path, String contents) throws IOException {
-		Files.asCharSink(new File(path), Charsets.UTF_8).write(contents);
+	protected static void createFile(String fileName, String contents) throws IOException {
+		try {
+			URI uri = new URI("file://" + fileName);
+			Path path = Paths.get(uri);
+			Files.write(path, contents.getBytes());
+		} catch (URISyntaxException e) {
+			e.printStackTrace();
+		}
+	}
+
+	protected static void updateFile(String path, String contents) throws IOException {
+		createFile(path, contents);
+		// For Mac OS, Linux OS, the call of Files.getLastModifiedTime is working for 1
+		// second.
+		// Here we wait for > 1s to be sure that call of Files.getLastModifiedTime will
+		// work.
+		try {
+			Thread.sleep(2000);
+		} catch (InterruptedException e) {
+			Thread.currentThread().interrupt();
+		}
 	}
 }
diff --git a/org.eclipse.lsp4xml/src/test/java/org/eclipse/lsp4xml/extensions/contentmodel/ContentModelManagerCacheTest.java b/org.eclipse.lsp4xml/src/test/java/org/eclipse/lsp4xml/extensions/contentmodel/ContentModelManagerCacheTest.java
index 01dbef77e1..e0d3b20ef3 100644
--- a/org.eclipse.lsp4xml/src/test/java/org/eclipse/lsp4xml/extensions/contentmodel/ContentModelManagerCacheTest.java
+++ b/org.eclipse.lsp4xml/src/test/java/org/eclipse/lsp4xml/extensions/contentmodel/ContentModelManagerCacheTest.java
@@ -13,6 +13,7 @@
 
 import java.io.File;
 import java.io.IOException;
+import java.nio.file.Path;
 
 import org.eclipse.lsp4xml.XMLAssert;
 import org.eclipse.lsp4xml.commons.BadLocationException;
@@ -74,7 +75,7 @@ public void testXSDCache() throws IOException, BadLocationException {
 				"    </xs:complexType>\r\n" + //
 				"  </xs:element>\r\n" + //
 				"</xs:schema>";
-		createFile(xsdPath, xsd);
+		updateFile(xsdPath, xsd);
 
 		XMLAssert.testCompletionFor(xml, null, xmlPath, 5 /* region, endregion, cdata, comment, label */,
 				c("label", "<label></label>"));
diff --git a/org.eclipse.lsp4xml/src/test/java/org/eclipse/lsp4xml/extensions/contentmodel/XMLSchemaCompletionExtensionsTest.java b/org.eclipse.lsp4xml/src/test/java/org/eclipse/lsp4xml/extensions/contentmodel/XMLSchemaCompletionExtensionsTest.java
index d39b30571e..ad0b49c58b 100644
--- a/org.eclipse.lsp4xml/src/test/java/org/eclipse/lsp4xml/extensions/contentmodel/XMLSchemaCompletionExtensionsTest.java
+++ b/org.eclipse.lsp4xml/src/test/java/org/eclipse/lsp4xml/extensions/contentmodel/XMLSchemaCompletionExtensionsTest.java
@@ -31,9 +31,6 @@
 import org.eclipse.lsp4xml.settings.XMLCompletionSettings;
 import org.junit.Test;
 
-import com.google.common.io.MoreFiles;
-import com.google.common.io.RecursiveDeleteOption;
-
 /**
  * XSD completion tests.
  *
@@ -392,7 +389,7 @@ public void completionWithXMLSchemaContentChanged() throws Exception {
 				+ "            </xs:sequence>\r\n"
 				// + " <xs:attribute name=\"variant\" type=\"xs:string\" use=\"required\"/>\r\n"
 				+ "        </xs:complexType>\r\n" + "    </xs:element>\r\n" + "</xs:schema>";
-		createFile(xsdPath, schema);
+		updateFile(xsdPath, schema);
 		XMLAssert.testCompletionFor(xmlLanguageService, xml, null, null, "target/resources.xml", 4, false);
 
 	}
diff --git a/org.eclipse.lsp4xml/src/test/java/org/eclipse/lsp4xml/extensions/contentmodel/model/FilesChangedTrackerTest.java b/org.eclipse.lsp4xml/src/test/java/org/eclipse/lsp4xml/extensions/contentmodel/model/FilesChangedTrackerTest.java
new file mode 100644
index 0000000000..0f209c7dc8
--- /dev/null
+++ b/org.eclipse.lsp4xml/src/test/java/org/eclipse/lsp4xml/extensions/contentmodel/model/FilesChangedTrackerTest.java
@@ -0,0 +1,40 @@
+/*******************************************************************************
+* Copyright (c) 2019 Red Hat Inc. and others.
+* All rights reserved. This program and the accompanying materials
+* which accompanies this distribution, and is available at
+* http://www.eclipse.org/legal/epl-v20.html
+*
+* Contributors:
+*     Red Hat Inc. - initial API and implementation
+*******************************************************************************/
+package org.eclipse.lsp4xml.extensions.contentmodel.model;
+
+import java.io.IOException;
+
+import org.eclipse.lsp4xml.extensions.contentmodel.BaseFileTempTest;
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * Test for {@link FilesChangedTracker}
+ * 
+ * @author Angelo ZERR
+ *
+ */
+public class FilesChangedTrackerTest extends BaseFileTempTest {
+
+	@Test
+	public void trackFile() throws IOException {
+		FilesChangedTracker tracker = new FilesChangedTracker();
+		String fileURI = tempDirUri.getPath() + "/track.xml";
+		createFile(fileURI, "<root />");
+		tracker.addFileURI("file://" + fileURI);
+
+		Assert.assertFalse(tracker.isDirty());
+
+		updateFile(fileURI, "<root />");
+		Assert.assertTrue(tracker.isDirty());
+		Assert.assertFalse(tracker.isDirty());
+
+	}
+}