diff --git a/src/main/java/moe/yushi/authlibinjector/httpd/URLProcessor.java b/src/main/java/moe/yushi/authlibinjector/httpd/URLProcessor.java
index 9fe7dd1..e771382 100644
--- a/src/main/java/moe/yushi/authlibinjector/httpd/URLProcessor.java
+++ b/src/main/java/moe/yushi/authlibinjector/httpd/URLProcessor.java
@@ -16,6 +16,7 @@
  */
 package moe.yushi.authlibinjector.httpd;
 
+import static moe.yushi.authlibinjector.util.IOUtils.CONTENT_TYPE_TEXT;
 import static moe.yushi.authlibinjector.util.IOUtils.transfer;
 import static moe.yushi.authlibinjector.util.Logging.log;
 import static moe.yushi.authlibinjector.util.Logging.Level.DEBUG;
@@ -131,7 +132,7 @@ public class URLProcessor {
 								result = filter.handle(domain, path, session);
 							} catch (Throwable e) {
 								log(WARNING, "An error occurred while processing request [" + session.getUri() + "]", e);
-								return Response.newFixedLength(Status.INTERNAL_ERROR, MIME_PLAINTEXT, "Internal Server Error");
+								return Response.newFixedLength(Status.INTERNAL_ERROR, CONTENT_TYPE_TEXT, "Internal Server Error");
 							}
 
 							if (result.isPresent()) {
@@ -147,11 +148,11 @@ public class URLProcessor {
 						return reverseProxy(session, target);
 					} catch (IOException e) {
 						log(WARNING, "Reverse proxy error", e);
-						return Response.newFixedLength(Status.BAD_GATEWAY, MIME_PLAINTEXT, "Bad Gateway");
+						return Response.newFixedLength(Status.BAD_GATEWAY, CONTENT_TYPE_TEXT, "Bad Gateway");
 					}
 				} else {
 					log(DEBUG, "No handler is found for [" + session.getUri() + "]");
-					return Response.newFixedLength(Status.NOT_FOUND, MIME_PLAINTEXT, "Not Found");
+					return Response.newFixedLength(Status.NOT_FOUND, CONTENT_TYPE_TEXT, "Not Found");
 				}
 			}
 		};
diff --git a/src/main/java/moe/yushi/authlibinjector/internal/fi/iki/elonen/HTTPSession.java b/src/main/java/moe/yushi/authlibinjector/internal/fi/iki/elonen/HTTPSession.java
index 4605272..98833d1 100644
--- a/src/main/java/moe/yushi/authlibinjector/internal/fi/iki/elonen/HTTPSession.java
+++ b/src/main/java/moe/yushi/authlibinjector/internal/fi/iki/elonen/HTTPSession.java
@@ -47,6 +47,7 @@
 package moe.yushi.authlibinjector.internal.fi.iki.elonen;
 
 import static java.nio.charset.StandardCharsets.ISO_8859_1;
+import static moe.yushi.authlibinjector.util.IOUtils.CONTENT_TYPE_TEXT;
 import java.io.BufferedInputStream;
 import java.io.BufferedReader;
 import java.io.ByteArrayInputStream;
@@ -275,11 +276,11 @@ class HTTPSession implements IHTTPSession {
 			// exception up the call stack.
 			throw ste;
 		} catch (IOException ioe) {
-			Response resp = Response.newFixedLength(Status.INTERNAL_ERROR, NanoHTTPD.MIME_PLAINTEXT, "SERVER INTERNAL ERROR: IOException: " + ioe.getMessage());
+			Response resp = Response.newFixedLength(Status.INTERNAL_ERROR, CONTENT_TYPE_TEXT, "SERVER INTERNAL ERROR: IOException: " + ioe.getMessage());
 			resp.send(this.outputStream);
 			NanoHTTPD.safeClose(this.outputStream);
 		} catch (ResponseException re) {
-			Response resp = Response.newFixedLength(re.getStatus(), NanoHTTPD.MIME_PLAINTEXT, re.getMessage());
+			Response resp = Response.newFixedLength(re.getStatus(), CONTENT_TYPE_TEXT, re.getMessage());
 			resp.send(this.outputStream);
 			NanoHTTPD.safeClose(this.outputStream);
 		} finally {
diff --git a/src/main/java/moe/yushi/authlibinjector/internal/fi/iki/elonen/NanoHTTPD.java b/src/main/java/moe/yushi/authlibinjector/internal/fi/iki/elonen/NanoHTTPD.java
index a7c4159..93d5ddb 100644
--- a/src/main/java/moe/yushi/authlibinjector/internal/fi/iki/elonen/NanoHTTPD.java
+++ b/src/main/java/moe/yushi/authlibinjector/internal/fi/iki/elonen/NanoHTTPD.java
@@ -46,6 +46,7 @@
  */
 package moe.yushi.authlibinjector.internal.fi.iki.elonen;
 
+import static moe.yushi.authlibinjector.util.IOUtils.CONTENT_TYPE_TEXT;
 import java.io.Closeable;
 import java.io.IOException;
 import java.io.InputStream;
@@ -201,10 +202,6 @@ public abstract class NanoHTTPD {
 	 */
 	public static final int SOCKET_READ_TIMEOUT = 5000;
 
-	/**
-	 * Common MIME type for dynamic content: plain text
-	 */
-	public static final String MIME_PLAINTEXT = "text/plain";
 	/**
 	 * logger to log to.
 	 */
@@ -291,7 +288,7 @@ public abstract class NanoHTTPD {
 	 * @return HTTP response, see class Response for details
 	 */
 	public Response serve(IHTTPSession session) {
-		return Response.newFixedLength(Status.NOT_FOUND, NanoHTTPD.MIME_PLAINTEXT, "Not Found");
+		return Response.newFixedLength(Status.NOT_FOUND, CONTENT_TYPE_TEXT, "Not Found");
 	}
 
 	/**
diff --git a/src/main/java/moe/yushi/authlibinjector/util/IOUtils.java b/src/main/java/moe/yushi/authlibinjector/util/IOUtils.java
index 5d5db2f..0061e5d 100644
--- a/src/main/java/moe/yushi/authlibinjector/util/IOUtils.java
+++ b/src/main/java/moe/yushi/authlibinjector/util/IOUtils.java
@@ -29,6 +29,7 @@ import java.net.URL;
 public final class IOUtils {
 
 	public static final String CONTENT_TYPE_JSON = "application/json; charset=utf-8";
+	public static final String CONTENT_TYPE_TEXT = "text/plain; charset=utf-8";
 
 	private static HttpURLConnection createConnection(String url, Proxy proxy) throws IOException {
 		if (proxy == null) {