diff --git a/VERSION b/VERSION
index ccbccc3..c043eea 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.2.0
+2.2.1
diff --git a/docs/Doxyfile b/docs/Doxyfile
index c96899f..e1c088e 100644
--- a/docs/Doxyfile
+++ b/docs/Doxyfile
@@ -48,7 +48,7 @@ PROJECT_NAME           = "SDI-12 for Arduino"
 # could be handy for archiving the generated documentation or if some version
 # control system is used.
 
-PROJECT_NUMBER         = 2.2.0
+PROJECT_NUMBER         = 2.2.1
 
 # Using the PROJECT_BRIEF tag one can provide an optional one line description
 # for a project that appears at the top of each page and should give viewer a
diff --git a/library.json b/library.json
index b7d1c8e..9db7a01 100644
--- a/library.json
+++ b/library.json
@@ -1,6 +1,6 @@
 {
   "name": "SDI-12",
-  "version": "2.2.0",
+  "version": "2.2.1",
   "keywords": "SDI-12, sdi12, communication, bus, sensor, Decagon",
   "description": "An Arduino library for SDI-12 communication with a wide variety of environmental sensors.",
   "repository": {
diff --git a/library.properties b/library.properties
index 25b51e6..b75d615 100644
--- a/library.properties
+++ b/library.properties
@@ -1,5 +1,5 @@
 name=SDI-12
-version=2.2.0
+version=2.2.1
 author=Kevin M. Smith <Kevin@elite-education.org>, Shannon Hicks <shicks@stroudcenter.org>
 maintainer=Sara Damiano <sdamiano@stroudcenter.org>
 sentence=An Arduino library for SDI-12 communication with a wide variety of environmental sensors.