diff --git a/headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/java/utils/SymbolCacheOnDisc.java b/headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/java/utils/SymbolCacheOnDisc.java
index 3d7b1e14f..ac21787d0 100644
--- a/headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/java/utils/SymbolCacheOnDisc.java
+++ b/headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/java/utils/SymbolCacheOnDisc.java
@@ -13,7 +13,9 @@ package org.springframework.ide.vscode.boot.java.utils;
 import java.io.File;
 import java.io.FileReader;
 import java.io.FileWriter;
+import java.io.IOException;
 import java.lang.reflect.Type;
+import java.nio.file.Files;
 import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
@@ -72,7 +74,13 @@ public class SymbolCacheOnDisc implements SymbolCache {
 
 		timestampedFiles = Arrays.stream(files)
 				.filter(file -> new File(file).exists())
-				.collect(Collectors.toMap(file -> file, file -> new File(file).lastModified(), (v1,v2) -> { throw new RuntimeException(String.format("Duplicate key for values %s and %s", v1, v2));}, TreeMap::new));
+				.collect(Collectors.toMap(file -> file, file -> {
+					try {
+						return Files.getLastModifiedTime(new File(file).toPath()).toMillis();
+					} catch (IOException e) {
+						throw new RuntimeException(e);
+					}
+				}, (v1,v2) -> { throw new RuntimeException(String.format("Duplicate key for values %s and %s", v1, v2));}, TreeMap::new));
 
 		save(cacheKey, generatedSymbols, timestampedFiles);
 	}
@@ -88,7 +96,13 @@ public class SymbolCacheOnDisc implements SymbolCache {
 
 				SortedMap<String, Long> timestampedFiles = Arrays.stream(files)
 						.filter(file -> new File(file).exists())
-						.collect(Collectors.toMap(file -> file, file -> new File(file).lastModified(),  (v1,v2) -> { throw new RuntimeException(String.format("Duplicate key for values %s and %s", v1, v2));}, TreeMap::new));
+						.collect(Collectors.toMap(file -> file, file -> {
+							try {
+								return Files.getLastModifiedTime(new File(file).toPath()).toMillis();
+							} catch (IOException e) {
+								throw new RuntimeException(e);
+							}
+						},  (v1,v2) -> { throw new RuntimeException(String.format("Duplicate key for values %s and %s", v1, v2));}, TreeMap::new));
 
 				if (isFileMatch(timestampedFiles, store.getTimestampedFiles())) {
 					this.stores.put(cacheKey, store);
diff --git a/headless-services/spring-boot-language-server/src/test/java/org/springframework/ide/vscode/boot/java/utils/test/SymbolCacheOnDiscTest.java b/headless-services/spring-boot-language-server/src/test/java/org/springframework/ide/vscode/boot/java/utils/test/SymbolCacheOnDiscTest.java
index b8f509fd5..a09df6fb1 100644
--- a/headless-services/spring-boot-language-server/src/test/java/org/springframework/ide/vscode/boot/java/utils/test/SymbolCacheOnDiscTest.java
+++ b/headless-services/spring-boot-language-server/src/test/java/org/springframework/ide/vscode/boot/java/utils/test/SymbolCacheOnDiscTest.java
@@ -31,7 +31,6 @@ import org.eclipse.lsp4j.SymbolInformation;
 import org.eclipse.lsp4j.SymbolKind;
 import org.junit.After;
 import org.junit.Before;
-import org.junit.Ignore;
 import org.junit.Test;
 import org.springframework.ide.vscode.boot.java.handlers.EnhancedSymbolInformation;
 import org.springframework.ide.vscode.boot.java.handlers.SymbolAddOnInformation;
@@ -229,7 +228,7 @@ public class SymbolCacheOnDiscTest {
 		assertEquals(new Range(new Position(6, 6), new Position(7, 7)), ranges[1]);
 	}
 
-	@Ignore @Test
+	@Test
 	public void testSymbolAddedToExistingFile() throws Exception {
 		Path file1 = Paths.get(tempDir.toAbsolutePath().toString(), "tempFile1");
 
@@ -265,7 +264,7 @@ public class SymbolCacheOnDiscTest {
 		assertEquals(2, cachedSymbols.length);
 	}
 
-	@Ignore @Test
+	@Test
 	public void testSymbolRemovedFromExistingFile() throws Exception {
 		Path file1 = Paths.get(tempDir.toAbsolutePath().toString(), "tempFile1");
 
@@ -293,7 +292,7 @@ public class SymbolCacheOnDiscTest {
 		assertEquals(0, cachedSymbols.length);
 	}
 
-	@Ignore @Test
+	@Test
 	public void testSymbolAddedToNewFile() throws Exception {
 		Path file1 = Paths.get(tempDir.toAbsolutePath().toString(), "tempFile1");
 		Path file2 = Paths.get(tempDir.toAbsolutePath().toString(), "tempFile2");