diff --git a/core/src/main/java/hudson/ClassicPluginStrategy.java b/core/src/main/java/hudson/ClassicPluginStrategy.java
index ef633bd83a..fe6ea4205e 100644
--- a/core/src/main/java/hudson/ClassicPluginStrategy.java
+++ b/core/src/main/java/hudson/ClassicPluginStrategy.java
@@ -85,7 +85,7 @@ public class ClassicPluginStrategy implements PluginStrategy {
         boolean isLinked = archive.getName().endsWith(".hpl");
         if (isLinked) {
             // resolve the .hpl file to the location of the manifest file
-            final String firstLine = IOUtils.readFirstLine(archive);
+            final String firstLine = IOUtils.readFirstLine(new FileInputStream(archive), "UTF-8");
             if (firstLine.startsWith("Manifest-Version:")) {
                 // this is the manifest already
             } else {
diff --git a/core/src/main/java/hudson/util/IOUtils.java b/core/src/main/java/hudson/util/IOUtils.java
index 5af4600741..975448dc58 100644
--- a/core/src/main/java/hudson/util/IOUtils.java
+++ b/core/src/main/java/hudson/util/IOUtils.java
@@ -122,17 +122,6 @@ public class IOUtils extends org.apache.commons.io.IOUtils {
         return PosixAPI.get().stat(f.getPath()).mode();
     }
 
-    /**
-     * Read the first line of a file
-     * @param file
-     * @return the first line of a file
-     * @throws IOException
-     * @since 1.422
-     */
-    public static String readFirstLine(File file) throws IOException {
-        return readFirstLine(new FileInputStream(file),null);
-    }
-
     /**
      * Read the first line of the given stream, close it, and return that line.
      *