diff --git a/c/include/libsbp/version.h b/c/include/libsbp/version.h
index 9d95c9b6b6..9a2eac1dab 100644
--- a/c/include/libsbp/version.h
+++ b/c/include/libsbp/version.h
@@ -21,14 +21,14 @@
  * \{ */
 
 /** Protocol major version. */
-#define SBP_MAJOR_VERSION 5
+#define SBP_MAJOR_VERSION 1
 /** Protocol minor version. */
-#define SBP_MINOR_VERSION 0
+#define SBP_MINOR_VERSION 2
 /** Protocol patch version. */
 #define SBP_PATCH_VERSION 3
 
 /** Full SBP version string. */
-#define SBP_VERSION "5.0.4-alpha"
+#define SBP_VERSION "1.2.3-alpha"
 
 /** Is this a staging branch? */
 #define SBP_STAGING 0
diff --git a/haskell/sbp.cabal b/haskell/sbp.cabal
index 1ef9868847..9e693f521e 100644
--- a/haskell/sbp.cabal
+++ b/haskell/sbp.cabal
@@ -1,5 +1,5 @@
 name:                  sbp
-version:               5.0.3-alpha
+version:               1.2.3-alpha
 synopsis:              SwiftNav's SBP Library
 homepage:              https://github.com/swift-nav/libsbp
 license:               MIT
diff --git a/javascript/sbp/RELEASE-VERSION b/javascript/sbp/RELEASE-VERSION
index a8a5353f80..96de3f358a 100644
--- a/javascript/sbp/RELEASE-VERSION
+++ b/javascript/sbp/RELEASE-VERSION
@@ -1 +1 @@
-5.0.4-alpha
\ No newline at end of file
+1.2.3-alpha
\ No newline at end of file
diff --git a/package-lock.json b/package-lock.json
index 749b65e4cf..f16571e3ed 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "sbp",
-  "version": "5.0.4-alpha",
+  "version": "1.2.3-alpha",
   "lockfileVersion": 2,
   "requires": true,
   "packages": {
     "": {
       "name": "sbp",
-      "version": "5.0.4-alpha",
+      "version": "1.2.3-alpha",
       "license": "MIT",
       "dependencies": {
         "binary-parser": "^1.7.0",
diff --git a/package.json b/package.json
index f8f4ab1a81..d860fa98a5 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sbp",
-  "version": "5.0.4-alpha",
+  "version": "1.2.3-alpha",
   "description": "libsbp bindings for JavaScript. More information here: http://swift-nav.github.io/libsbp/",
   "files": [
     "javascript/*",
diff --git a/python/sbp/RELEASE-VERSION b/python/sbp/RELEASE-VERSION
index 26611488b0..e2cac26c1a 100644
--- a/python/sbp/RELEASE-VERSION
+++ b/python/sbp/RELEASE-VERSION
@@ -1 +1 @@
-5.0.3
\ No newline at end of file
+1.2.3
\ No newline at end of file
diff --git a/rust/sbp/Cargo.toml b/rust/sbp/Cargo.toml
index 4dfb263966..955df882e0 100644
--- a/rust/sbp/Cargo.toml
+++ b/rust/sbp/Cargo.toml
@@ -7,7 +7,7 @@
 
 [package]
 name = "sbp"
-version = "5.0.4-alpha"
+version = "1.2.3"
 description = "Rust native implementation of SBP (Swift Binary Protocol) for communicating with devices made by Swift Navigation"
 authors = ["Swift Navigation <dev@swiftnav.com>"]
 repository = "https://github.com/swift-nav/libsbp"
diff --git a/rust/sbp2json/Cargo.toml b/rust/sbp2json/Cargo.toml
index 35c00a00b4..9e9b1a1c96 100644
--- a/rust/sbp2json/Cargo.toml
+++ b/rust/sbp2json/Cargo.toml
@@ -7,7 +7,7 @@
 
 [package]
 name = "sbp2json"
-version = "5.0.4-alpha"
+version = "1.2.3-unreleased"
 repository = "https://github.com/swift-nav/libsbp"
 description = "Rust native implementation of SBP (Swift Binary Protocol) to JSON conversion tools"
 authors = ["Swift Navigation <dev@swiftnav.com>"]