diff --git a/c/include/libsbp/version.h b/c/include/libsbp/version.h
index 75b072c06c..b542488cff 100644
--- a/c/include/libsbp/version.h
+++ b/c/include/libsbp/version.h
@@ -25,7 +25,7 @@
 /** Protocol minor version. */
 #define SBP_MINOR_VERSION 5
 /** Protocol patch version. */
-#define SBP_PATCH_VERSION 0
+#define SBP_PATCH_VERSION 1
 
 /** \} */
 
diff --git a/default.nix b/default.nix
index 8fe822c996..4cbc4abc29 100644
--- a/default.nix
+++ b/default.nix
@@ -16,10 +16,12 @@ stdenv.mkDerivation rec {
     python27Packages.setuptools
     python27Packages.virtualenv
     python27Packages.pip
+    python27Packages.cython
     python37Full
     python37Packages.setuptools
     python27Packages.virtualenv
     python37Packages.pip
+    python37Packages.cython
     nodejs
     coreutils
     bash
@@ -29,6 +31,8 @@ stdenv.mkDerivation rec {
     cmake
     git
     which
+    llvm
+    libcxxStdenv
   ];
   shellHook = ''
     [[ -z "$SOURCE_DATE_EPOCH" ]] || unset SOURCE_DATE_EPOCH
diff --git a/haskell/sbp.cabal.m4 b/haskell/sbp.cabal.m4
index 25c9a203a6..6adfe45e9a 100644
--- a/haskell/sbp.cabal.m4
+++ b/haskell/sbp.cabal.m4
@@ -1,5 +1,5 @@
 name:                  sbp
-version:               2.5.0
+version:               2.5.1
 synopsis:              SwiftNav's SBP Library
 homepage:              https://github.com/swift-nav/libsbp
 license:               LGPL-3
diff --git a/package.json b/package.json
index 6b12749c60..0108c42fdf 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sbp",
-  "version": "2.5.0",
+  "version": "2.5.1",
   "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 73462a5a13..4fd0fe3cd5 100644
--- a/python/sbp/RELEASE-VERSION
+++ b/python/sbp/RELEASE-VERSION
@@ -1 +1 @@
-2.5.1
+2.5.1
\ No newline at end of file
diff --git a/python/sbp/tracking.py b/python/sbp/tracking.py
index 0e32fa6cf9..305d552973 100644
--- a/python/sbp/tracking.py
+++ b/python/sbp/tracking.py
@@ -1071,6 +1071,15 @@ def to_binary(self):
     self.payload = MsgTrackingIqDepB._parser.build(c)
     return self.pack()
 
+  def into_buffer(self, buf, offset):
+    """Produce a framed/packed SBP message into the provided buffer and offset.
+
+    """
+    self.payload = containerize(exclude_fields(self))
+    self.parser = MsgTrackingIqDepB._parser
+    self.stream_payload.reset(buf, offset)
+    return self.pack_into(buf, offset, self._build_payload)
+
   def to_json_dict(self):
     self.to_binary()
     d = super( MsgTrackingIqDepB, self).to_json_dict()
@@ -1166,7 +1175,7 @@ def into_buffer(self, buf, offset):
 
     """
     self.payload = containerize(exclude_fields(self))
-    self.parser = MsgTrackingIqDep._parser
+    self.parser = MsgTrackingIqDepA._parser
     self.stream_payload.reset(buf, offset)
     return self.pack_into(buf, offset, self._build_payload)