diff --git a/doc/api/deprecations.md b/doc/api/deprecations.md
index f10265b9ddd98a..ffe35b6d942b5c 100644
--- a/doc/api/deprecations.md
+++ b/doc/api/deprecations.md
@@ -695,6 +695,9 @@ Type: End-of-Life
 
 <!-- YAML
 changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/55175
+    description: Runtime deprecation.
   - version: v6.12.0
     pr-url: https://github.com/nodejs/node/pull/10116
     description: A deprecation code has been assigned.
@@ -703,7 +706,7 @@ changes:
     description: Documentation-only deprecation.
 -->
 
-Type: Documentation-only
+Type: Runtime
 
 The [`SlowBuffer`][] class is deprecated. Please use
 [`Buffer.allocUnsafeSlow(size)`][] instead.
diff --git a/lib/buffer.js b/lib/buffer.js
index 6294eae2fb5093..9b116eabe69d36 100644
--- a/lib/buffer.js
+++ b/lib/buffer.js
@@ -88,6 +88,7 @@ const {
   kIsEncodingSymbol,
   defineLazyProperties,
   encodingsMap,
+  deprecate,
 } = require('internal/util');
 const {
   isAnyArrayBuffer,
@@ -1322,7 +1323,10 @@ function isAscii(input) {
 
 module.exports = {
   Buffer,
-  SlowBuffer,
+  SlowBuffer: deprecate(
+    SlowBuffer,
+    'SlowBuffer() is deprecated. Please use Buffer.allowUnsafeSlow()',
+    'DEP0030'),
   transcode,
   isUtf8,
   isAscii,