diff --git a/doc/guides/rel_notes/deprecation.rst b/doc/guides/rel_notes/deprecation.rst
index 2e082499b8..0f6f1df12a 100644
--- a/doc/guides/rel_notes/deprecation.rst
+++ b/doc/guides/rel_notes/deprecation.rst
@@ -87,7 +87,6 @@ Deprecation Notices
   The following static fields will be moved as dynamic:
 
   - ``timestamp``
-  - ``userdata`` / ``udata64``
   - ``seqn``
 
   As a consequence, the layout of the ``struct rte_mbuf`` will be re-arranged,
diff --git a/doc/guides/rel_notes/release_20_11.rst b/doc/guides/rel_notes/release_20_11.rst
index bae39b2dd0..70cefb6d07 100644
--- a/doc/guides/rel_notes/release_20_11.rst
+++ b/doc/guides/rel_notes/release_20_11.rst
@@ -442,6 +442,9 @@ API Changes
   the structures ``rte_mbuf`` and ``rte_mbuf_ext_shared_info``.
   The field ``refcnt`` is remaining from the old unions.
 
+* mbuf: Removed the unioned fields ``userdata`` and ``udata64``
+  from the structure ``rte_mbuf``. It is replaced with dynamic fields.
+
 * pci: Removed the ``rte_kernel_driver`` enum defined in rte_dev.h and
   replaced with a private enum in the PCI subsystem.
 
diff --git a/lib/librte_kni/rte_kni_common.h b/lib/librte_kni/rte_kni_common.h
index 21b477f0aa..36d66e2ffa 100644
--- a/lib/librte_kni/rte_kni_common.h
+++ b/lib/librte_kni/rte_kni_common.h
@@ -86,7 +86,7 @@ struct rte_kni_mbuf {
 	uint16_t data_len;      /**< Amount of data in segment buffer. */
 
 	/* fields on second cache line */
-	char pad3[8] __attribute__((__aligned__(RTE_CACHE_LINE_MIN_SIZE)));
+	__attribute__((__aligned__(RTE_CACHE_LINE_MIN_SIZE)))
 	void *pool;
 	void *next;             /**< Physical address of next mbuf in kernel. */
 };
diff --git a/lib/librte_mbuf/rte_mbuf_core.h b/lib/librte_mbuf/rte_mbuf_core.h
index 065d87d28a..a65eaaf692 100644
--- a/lib/librte_mbuf/rte_mbuf_core.h
+++ b/lib/librte_mbuf/rte_mbuf_core.h
@@ -599,12 +599,6 @@ struct rte_mbuf {
 	/* second cache line - fields only used in slow path or on TX */
 	RTE_MARKER cacheline1 __rte_cache_min_aligned;
 
-	RTE_STD_C11
-	union {
-		void *userdata;   /**< Can be used for external metadata */
-		uint64_t udata64; /**< Allow 8-byte userdata on 32-bit */
-	};
-
 	struct rte_mempool *pool; /**< Pool from which mbuf was allocated. */
 	struct rte_mbuf *next;    /**< Next segment of scattered packet. */
 
@@ -662,7 +656,7 @@ struct rte_mbuf {
 	 */
 	struct rte_mbuf_ext_shared_info *shinfo;
 
-	uint64_t dynfield1[2]; /**< Reserved for dynamic fields. */
+	uint64_t dynfield1[3]; /**< Reserved for dynamic fields. */
 } __rte_cache_aligned;
 
 /**