diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8bcc4a03141b..231cddb2709d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,9 @@ section the body of the GitHub release, and refuses a version without one. `scri
 
 ## Unreleased
 
+- Word, Excel and PowerPoint files that a mail or file app labels the old way offer to open
+  in the app again.
+
 ## 4.21.0
 
 - Spreadsheet cells can be formatted: fill, bold, italic, underline, strikethrough,
diff --git a/app/src/androidTest/java/app/opendocument/droid/test/SupportedFormatsTest.kt b/app/src/androidTest/java/app/opendocument/droid/test/SupportedFormatsTest.kt
index a72061c8d43c..74048bd83514 100644
--- a/app/src/androidTest/java/app/opendocument/droid/test/SupportedFormatsTest.kt
+++ b/app/src/androidTest/java/app/opendocument/droid/test/SupportedFormatsTest.kt
@@ -141,6 +141,28 @@ class SupportedFormatsTest {
         }
     }
 
+    /**
+     * A spelling the core does not name, but a mail or file app sends, reaches us on both sides.
+     */
+    @Test
+    fun anAliasSpellingReachesUs() {
+        for ((alias, named) in SupportedDocumentTypes.MIME_ALIASES) {
+            Assert.assertTrue(
+                "the app does not offer for $alias",
+                SupportedDocumentTypes.isSupported(alias, null),
+            )
+            Assert.assertTrue(
+                "the manifest does not offer for $alias",
+                resolvesToUs(alias, "document"),
+            )
+            Assert.assertEquals(
+                "$alias is not read as $named",
+                SupportedDocumentTypes.canonicalMimeType(named),
+                SupportedDocumentTypes.canonicalMimeType(alias),
+            )
+        }
+    }
+
     /** And the same route stays shut for what the app does not claim. */
     @Test
     fun aFileWithNoMimeTypeAndAnUnrelatedExtensionReachesNobody() {
diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 9ee3868510a5..7a31859abf93 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -282,6 +282,23 @@
                 <data android:mimeType="application/x-iwork-numbers-sffnumbers" />
                 <data android:mimeType="application/vnd.apple.keynote" />
                 <data android:mimeType="application/x-iwork-keynote-sffkey" />
+                <!--
+                     spellings odrcore does not name, which SupportedDocumentTypes.MIME_ALIASES
+                     maps to ones it does. the two lists have to match.
+                -->
+                <data android:mimeType="application/x-msword" />
+                <data android:mimeType="application/doc" />
+                <data android:mimeType="application/x-doc" />
+                <data android:mimeType="application/vnd.msword" />
+                <data android:mimeType="application/word" />
+                <data android:mimeType="application/x-msexcel" />
+                <data android:mimeType="application/x-ms-excel" />
+                <data android:mimeType="application/x-excel" />
+                <data android:mimeType="application/excel" />
+                <data android:mimeType="application/vnd.msexcel" />
+                <data android:mimeType="application/x-mspowerpoint" />
+                <data android:mimeType="application/powerpoint" />
+                <data android:mimeType="application/x-powerpoint" />
                 <!--
                      the octet-stream a provider volunteers when it knows nothing better.
                      only the filename can answer for it - the pathPattern filter below.
diff --git a/app/src/main/java/app/opendocument/droid/background/SupportedDocumentTypes.kt b/app/src/main/java/app/opendocument/droid/background/SupportedDocumentTypes.kt
index b81afa47be02..45fe94ae6047 100644
--- a/app/src/main/java/app/opendocument/droid/background/SupportedDocumentTypes.kt
+++ b/app/src/main/java/app/opendocument/droid/background/SupportedDocumentTypes.kt
@@ -59,8 +59,30 @@ object SupportedDocumentTypes {
     /** Every mime type spelling odrcore accepts for a format [CoreLoader] renders. */
     private val CORE_MIME_TYPES: Set<String> by lazy { mimeTypesOf(CORE_FILE_TYPES) }
 
+    /**
+     * Spellings of the binary office formats that mail and file apps send and odrcore does not
+     * name, each mapped to one it does. The manifest claims them as well; the bytes decide once the
+     * file is cached.
+     */
+    internal val MIME_ALIASES =
+        mapOf(
+            "application/x-msword" to "application/msword",
+            "application/doc" to "application/msword",
+            "application/x-doc" to "application/msword",
+            "application/vnd.msword" to "application/msword",
+            "application/word" to "application/msword",
+            "application/x-msexcel" to "application/vnd.ms-excel",
+            "application/x-ms-excel" to "application/vnd.ms-excel",
+            "application/x-excel" to "application/vnd.ms-excel",
+            "application/excel" to "application/vnd.ms-excel",
+            "application/vnd.msexcel" to "application/vnd.ms-excel",
+            "application/x-mspowerpoint" to "application/vnd.ms-powerpoint",
+            "application/powerpoint" to "application/vnd.ms-powerpoint",
+            "application/x-powerpoint" to "application/vnd.ms-powerpoint",
+        )
+
     /** The same for everything the app offers itself for. */
-    val MIME_TYPES: Set<String> by lazy { mimeTypesOf(CLAIMED_FILE_TYPES) }
+    val MIME_TYPES: Set<String> by lazy { mimeTypesOf(CLAIMED_FILE_TYPES) + MIME_ALIASES.keys }
 
     /**
      * The extension fallback, for the `application/octet-stream` providers regularly volunteer and
@@ -83,12 +105,14 @@ object SupportedDocumentTypes {
             return null
         }
 
-        val fileType = Odr.fileTypeByMimetype(mimeType) ?: return mimeType
+        val named = MIME_ALIASES[mimeType.lowercase()] ?: mimeType
+
+        val fileType = Odr.fileTypeByMimetype(named) ?: return named
         if (fileType == FileType.UNKNOWN) {
-            return mimeType
+            return named
         }
 
-        return Odr.mimetypeByFileType(fileType) ?: mimeType
+        return Odr.mimetypeByFileType(fileType) ?: named
     }
 
     /** Whether [CoreLoader] is expected to render this - see [CORE_FILE_TYPES]. */