diff --git a/poi-ooxml/src/test/java/org/apache/poi/ooxml/TestDetectAsOOXML.java b/poi-ooxml/src/test/java/org/apache/poi/ooxml/TestDetectAsOOXML.java
index 6d3708c139..1255f1da3f 100644
--- a/poi-ooxml/src/test/java/org/apache/poi/ooxml/TestDetectAsOOXML.java
+++ b/poi-ooxml/src/test/java/org/apache/poi/ooxml/TestDetectAsOOXML.java
@@ -54,10 +54,6 @@ class TestDetectAsOOXML {
     void testDetectAsPOIFS(String file, FileMagic fm) throws IOException {
         try (InputStream is = FileMagic.prepareToCheckMagic(openSampleFileStream(file))) {
             FileMagic act = FileMagic.valueOf(is);
-
-            assertEquals(act == FileMagic.OOXML, DocumentFactoryHelper.hasOOXMLHeader(is),
-                "OOXML files should be detected, others not");
-
             assertEquals(fm, act, "file magic failed for " + file);
         }
     }
@@ -70,7 +66,7 @@ class TestDetectAsOOXML {
         InputStream is = FileMagic.prepareToCheckMagic(testInput);
 
         // detect header
-        assertFalse(DocumentFactoryHelper.hasOOXMLHeader(is));
+        assertFalse(FileMagic.valueOf(is) == FileMagic.OOXML);
 
         // check if InputStream is still intact
         byte[] act = IOUtils.toByteArray(is);
diff --git a/poi/src/main/java/org/apache/poi/poifs/filesystem/DocumentFactoryHelper.java b/poi/src/main/java/org/apache/poi/poifs/filesystem/DocumentFactoryHelper.java
index 6b9b749362..4ca1e8ee53 100644
--- a/poi/src/main/java/org/apache/poi/poifs/filesystem/DocumentFactoryHelper.java
+++ b/poi/src/main/java/org/apache/poi/poifs/filesystem/DocumentFactoryHelper.java
@@ -28,7 +28,6 @@ import org.apache.poi.EncryptedDocumentException;
 import org.apache.poi.poifs.crypt.Decryptor;
 import org.apache.poi.poifs.crypt.EncryptionInfo;
 import org.apache.poi.util.Internal;
-import org.apache.poi.util.Removal;
 
 /**
  * A small base class for the various factories, e.g. WorkbookFactory,
@@ -100,22 +99,4 @@ public final class DocumentFactoryHelper {
             throw new IOException(e);
         }
     }
-
-    /**
-     * Checks that the supplied InputStream (which MUST
-     *  support mark and reset) has a OOXML (zip) header at the start of it.<p>
-     *
-     * If unsure if your InputStream does support mark / reset,
-     *  use {@link FileMagic#prepareToCheckMagic(InputStream)} to wrap it and make
-     *  sure to always use that, and not the original!
-     *
-     * @param inp An InputStream which supports either mark/reset
-     *
-     * @deprecated in 3.17-beta2, use {@link FileMagic#valueOf(InputStream)} == FileMagic.OOXML instead
-     */
-    @Deprecated
-    @Removal(version="4.0")
-    public static boolean hasOOXMLHeader(InputStream inp) throws IOException {
-        return FileMagic.valueOf(inp) == FileMagic.OOXML;
-    }
 }