diff --git a/CHANGES.md b/CHANGES.md
index e4474a1..c873df8 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -89,4 +89,4 @@ A hierarchy of frame buffer classes has been added. These allow for flexible ada
 
 ## press_keys (.hpp, .cpp)
 
-This class implements the Buttons Extension: 6 mechanical press buttons that replace the touch keys. To be used, at compile time, BUTTONS_EXTENSION must be #defined. The touch_keys class will then not be included.  
\ No newline at end of file
+This class implements the Buttons Extension: 6 mechanical press buttons that replace the touch keys. To be used, at compile time, BUTTONS_EXTENSION must be #defined. The `TouchKeys` class will then **not** be included.  
\ No newline at end of file
diff --git a/README.md b/README.md
index 182ee1d..df57313 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,8 @@
-# ESP-IDF-InkPlate Library Version 0.9.3
+# ESP-IDF-InkPlate Library Version 0.9.4
+
+(March 3, 2021)
+
+Version 0.9.4: Added `PressKeys` class in support of the Buttons Extended Case as described [here](https://github.com/turgu1/InkPlate-6-Extended-Case). To be used, at compile time, BUTTONS_EXTENSION must be #defined. The `TouchKeys` class will then **not** be included.
 
 (March 2, 2021)
 
diff --git a/include/drivers/press_keys.hpp b/include/drivers/press_keys.hpp
index fc5bfba..931e011 100644
--- a/include/drivers/press_keys.hpp
+++ b/include/drivers/press_keys.hpp
@@ -6,7 +6,7 @@
 class PressKeys : NonCopyable 
 {
   public:
-    enum class Key : uint8_t { KEY_0, KEY_1, KEY_2, KEY_3, KEY_4, KEY_5 };
+    enum class Key : uint8_t { U2, U4, U1, U5, U3, U6 };
 
     PressKeys(MCP23017 & _mcp) : mcp(_mcp) {}
     bool setup();
@@ -16,7 +16,7 @@ class PressKeys : NonCopyable
      * 
      * Read one of the six presskeys.
      * 
-     * @param key presskey  (KEY_0, KEY_1, or KEY_2)
+     * @param key presskey  (U1 .. U6)
      * @return uint8_t 1 if pressed, 0 if not
      */
     uint8_t read_key(Key key);
diff --git a/library.json b/library.json
index f55f6fb..778f7c9 100644
--- a/library.json
+++ b/library.json
@@ -1,6 +1,6 @@
 {
   "name": "ESP-IDF-Inkplate",
-  "version": "0.9.3",
+  "version": "0.9.4",
   "description": "Implements common functions for Inkplate e-paper displays",
   "keywords": "e-ink, e-paper, display, esp32",
   "repository":