diff --git a/build_sysroot/Cargo.lock b/build_sysroot/Cargo.lock
index dd5228d3ba4..201b74f7f76 100644
--- a/build_sysroot/Cargo.lock
+++ b/build_sysroot/Cargo.lock
@@ -56,7 +56,7 @@ dependencies = [
 
 [[package]]
 name = "compiler_builtins"
-version = "0.1.42"
+version = "0.1.43"
 dependencies = [
  "rustc-std-workspace-core",
 ]
diff --git a/build_sysroot/prepare_sysroot_src.sh b/build_sysroot/prepare_sysroot_src.sh
index 2b0feb93d4d..54b7a94750c 100755
--- a/build_sysroot/prepare_sysroot_src.sh
+++ b/build_sysroot/prepare_sysroot_src.sh
@@ -32,7 +32,7 @@ popd
 git clone https://github.com/rust-lang/compiler-builtins.git || echo "rust-lang/compiler-builtins has already been cloned"
 pushd compiler-builtins
 git checkout -- .
-git checkout 0.1.42
+git checkout 0.1.43
 git apply ../../crate_patches/000*-compiler-builtins-*.patch
 popd
 
diff --git a/rust-toolchain b/rust-toolchain
index 16df0ed7508..fea0dba33f7 100644
--- a/rust-toolchain
+++ b/rust-toolchain
@@ -1,3 +1,3 @@
 [toolchain]
-channel = "nightly-2021-05-11"
+channel = "nightly-2021-05-18"
 components = ["rust-src", "rustc-dev", "llvm-tools-preview"]