diff --git a/spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/jar/Handler.java b/spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/jar/Handler.java
index 4a64223cc03..917f35706d7 100644
--- a/spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/jar/Handler.java
+++ b/spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/jar/Handler.java
@@ -203,7 +203,34 @@ public class Handler extends URLStreamHandler {
 	}
 
 	private void setFile(URL context, String file) {
-		setURL(context, JAR_PROTOCOL, null, -1, null, null, file, null, null);
+		setURL(context, JAR_PROTOCOL, null, -1, null, null, normalize(file), null, null);
+	}
+
+	private String normalize(String file) {
+		int afterLastSeparatorIndex = file.lastIndexOf(SEPARATOR) + SEPARATOR.length();
+		String afterSeparator = file.substring(afterLastSeparatorIndex);
+		afterSeparator = replaceParentDir(afterSeparator);
+		afterSeparator = replaceCurrentDir(afterSeparator);
+		return file.substring(0, afterLastSeparatorIndex) + afterSeparator;
+	}
+
+	private String replaceParentDir(String file) {
+		int parentDirIndex;
+		while ((parentDirIndex = file.indexOf("/../")) >= 0) {
+			int precedingSlashIndex = file.lastIndexOf('/', parentDirIndex - 1);
+			if (precedingSlashIndex >= 0) {
+				file = file.substring(0, precedingSlashIndex)
+						+ file.substring(parentDirIndex + 3);
+			}
+			else {
+				file = file.substring(parentDirIndex + 4);
+			}
+		}
+		return file;
+	}
+
+	private String replaceCurrentDir(String file) {
+		return file.replace("/./", "/");
 	}
 
 	@Override
diff --git a/spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/jar/HandlerTests.java b/spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/jar/HandlerTests.java
index 2fc34b35b10..4744e94199f 100644
--- a/spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/jar/HandlerTests.java
+++ b/spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/jar/HandlerTests.java
@@ -136,6 +136,36 @@ public class HandlerTests {
 								new URL("jar:file:/test.jar!/BOOT-INF/classes/foo.txt")));
 	}
 
+	@Test
+	public void urlWithSpecReferencingParentDirectory() throws MalformedURLException {
+		assertStandardAndCustomHandlerUrlsAreEqual(
+				"file:/test.jar!/BOOT-INF/classes!/xsd/folderA/a.xsd",
+				"../folderB/b.xsd");
+	}
+
+	@Test
+	public void urlWithSpecReferencingAncestorDirectoryOutsideJarStopsAtJarRoot()
+			throws MalformedURLException {
+		assertStandardAndCustomHandlerUrlsAreEqual(
+				"file:/test.jar!/BOOT-INF/classes!/xsd/folderA/a.xsd",
+				"../../../../../../folderB/b.xsd");
+	}
+
+	@Test
+	public void urlWithSpecReferencingCurrentDirectory() throws MalformedURLException {
+		assertStandardAndCustomHandlerUrlsAreEqual(
+				"file:/test.jar!/BOOT-INF/classes!/xsd/folderA/a.xsd",
+				"./folderB/./b.xsd");
+	}
+
+	private void assertStandardAndCustomHandlerUrlsAreEqual(String context, String spec)
+			throws MalformedURLException {
+		URL standardUrl = new URL(new URL("jar:" + context), spec);
+		URL customHandlerUrl = new URL(new URL("jar", null, -1, context, this.handler),
+				spec);
+		assertThat(customHandlerUrl.toString()).isEqualTo(standardUrl.toString());
+	}
+
 	private URL createUrl(String file) throws MalformedURLException {
 		return new URL("jar", null, -1, file, this.handler);
 	}