diff --git a/CHANGELOG.md b/CHANGELOG.md
index 625dcd9d..9972e707 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 ## [Unreleased]
 
 ### Added
+- Add support for compiling on Mac (and clang)
 - An option for resetting stalled validation metrics
 - Add CMAKE options to disable compilation for specific GPU SM types
 - An option to print word-level translation scores
@@ -57,6 +58,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Compilation with CUDA 10.1
 
 ### Changed
+- Combine two for-loops in nth_element.cpp on CPU
 - Revert LayerNorm eps to old position, i.e. sigma' = sqrt(sigma^2 + eps)
 - Downgrade NCCL to 2.3.7 as 2.4.2 is buggy (hangs with larger models)
 - Return error signal on SIGTERM
diff --git a/VERSION b/VERSION
index e8eb33e5..a5969e9f 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-v1.8.40
+v1.8.51
diff --git a/regression-tests b/regression-tests
index 448cc1a8..6a08849b 160000
--- a/regression-tests
+++ b/regression-tests
@@ -1 +1 @@
-Subproject commit 448cc1a8ff2f37b102695dc5cea89cf285202ee7
+Subproject commit 6a08849b23f6c14eefbe12f4eb73dc638b962587
diff --git a/src/3rd_party/fbgemm b/src/3rd_party/fbgemm
index f78e6098..84e66a97 160000
--- a/src/3rd_party/fbgemm
+++ b/src/3rd_party/fbgemm
@@ -1 +1 @@
-Subproject commit f78e60988329b9207d086c743cafce1ac1bea3ab
+Subproject commit 84e66a976046180187724aff60a236c5378fde7c