diff --git a/src/main/org/apache/tools/zip/ZipOutputStream.java b/src/main/org/apache/tools/zip/ZipOutputStream.java
index c1d73b3df..0d222912e 100644
--- a/src/main/org/apache/tools/zip/ZipOutputStream.java
+++ b/src/main/org/apache/tools/zip/ZipOutputStream.java
@@ -349,7 +349,7 @@ public class ZipOutputStream extends FilterOutputStream {
     public void setEncoding(final String encoding) {
         this.encoding = encoding;
         this.zipEncoding = ZipEncodingHelper.getZipEncoding(encoding);
-        useUTF8Flag &= ZipEncodingHelper.isUTF8(encoding);
+        useUTF8Flag = useUTF8Flag && ZipEncodingHelper.isUTF8(encoding);
     }
 
     /**