diff --git a/headless-services/jdt-ls-extension/org.springframework.tooling.jdt.ls.commons.test/src/org/springframework/tooling/jdt/ls/commons/test/ClasspathListenerHandlerTest.java b/headless-services/jdt-ls-extension/org.springframework.tooling.jdt.ls.commons.test/src/org/springframework/tooling/jdt/ls/commons/test/ClasspathListenerHandlerTest.java
index dc9f2dacf..df8bfe2c1 100644
--- a/headless-services/jdt-ls-extension/org.springframework.tooling.jdt.ls.commons.test/src/org/springframework/tooling/jdt/ls/commons/test/ClasspathListenerHandlerTest.java
+++ b/headless-services/jdt-ls-extension/org.springframework.tooling.jdt.ls.commons.test/src/org/springframework/tooling/jdt/ls/commons/test/ClasspathListenerHandlerTest.java
@@ -156,9 +156,6 @@ public class ClasspathListenerHandlerTest {
 	}
 
 	@Test public void sourceJar() throws Exception {
-		IEclipsePreferences m2eprefs = InstanceScope.INSTANCE.getNode("org.eclipse.m2e.core");
-		m2eprefs.putBoolean("eclipse.m2.downloadSources", true);
-		System.out.println("downloadSources = " + m2eprefs.get("eclipse.m2.downloadSources", null));
 		String projectName = "maven-with-jar-dependency";
 		IProject project = createTestProject(projectName);
 		File loc = project.getLocation().toFile();
diff --git a/headless-services/jdt-ls-extension/org.springframework.tooling.jdt.ls.commons/src/org/springframework/tooling/jdt/ls/commons/classpath/ClasspathUtil.java b/headless-services/jdt-ls-extension/org.springframework.tooling.jdt.ls.commons/src/org/springframework/tooling/jdt/ls/commons/classpath/ClasspathUtil.java
index 5f3e5e90c..26c278154 100644
--- a/headless-services/jdt-ls-extension/org.springframework.tooling.jdt.ls.commons/src/org/springframework/tooling/jdt/ls/commons/classpath/ClasspathUtil.java
+++ b/headless-services/jdt-ls-extension/org.springframework.tooling.jdt.ls.commons/src/org/springframework/tooling/jdt/ls/commons/classpath/ClasspathUtil.java
@@ -19,10 +19,13 @@ import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
+import java.util.concurrent.atomic.AtomicBoolean;
 
 import org.eclipse.core.resources.IProject;
 import org.eclipse.core.resources.ResourcesPlugin;
 import org.eclipse.core.runtime.IPath;
+import org.eclipse.core.runtime.preferences.IEclipsePreferences;
+import org.eclipse.core.runtime.preferences.InstanceScope;
 import org.eclipse.jdt.core.IClasspathEntry;
 import org.eclipse.jdt.core.IJavaProject;
 import org.eclipse.jdt.core.IPackageFragmentRoot;
@@ -68,6 +71,7 @@ public class ClasspathUtil {
 
 	public static Classpath resolve(IJavaProject javaProject, Logger logger) throws Exception {
 		//log("resolving classpath " + javaProject.getElementName() +" ...");
+		enableDownloadSources();
 
 		List<CPE> cpEntries = new ArrayList<>();
 		
@@ -91,10 +95,19 @@ public class ClasspathUtil {
 		return classpath;
 	}
 	
+	private static AtomicBoolean enabledDownloadSources = new AtomicBoolean(false);
+	
 	public static CPE createCpe(IJavaProject javaProject, IClasspathEntry entry) throws MalformedURLException, JavaModelException {
 		return createCpe(getSystemLibraryPaths(javaProject), javaProject, entry);
 	}
 	
+	private static void enableDownloadSources() {
+		if (!enabledDownloadSources.getAndSet(true)) {
+			IEclipsePreferences m2eprefs = InstanceScope.INSTANCE.getNode("org.eclipse.m2e.core");
+			m2eprefs.putBoolean("eclipse.m2.downloadSources", true);
+		}
+	}
+
 	private static CPE createCpe(Set<String> systemLibs, IJavaProject javaProject, IClasspathEntry entry)
 			throws MalformedURLException, JavaModelException {
 		String kind = toContentKind(entry);