diff --git a/.github/workflows/cargo_llvm_cov.yml b/.github/workflows/cargo_llvm_cov.yml
index edf19e52842..fdac8f6fcaf 100644
--- a/.github/workflows/cargo_llvm_cov.yml
+++ b/.github/workflows/cargo_llvm_cov.yml
@@ -47,7 +47,7 @@ jobs:
       - name: Install llvm-tools
         run: |
           # TOOLCHAIN=$(rustup show active-toolchain | cut -d ' ' -f 1)
-          TOOLCHAIN=nightly
+          TOOLCHAIN=nightly-x86_64-unknown-linux-gnu
           rustup component add llvm-tools --toolchain "$TOOLCHAIN"
           LLVM_PROFDATA=$HOME/.rustup/toolchains/$TOOLCHAIN/lib/rustlib/x86_64-unknown-linux-gnu/bin/llvm-profdata
           echo "LLVM_PROFDATA=$LLVM_PROFDATA" >> $GITHUB_ENV
diff --git a/scripts/simtest/simtest-cov.sh b/scripts/simtest/simtest-cov.sh
index 498742d7bef..2a91d265068 100755
--- a/scripts/simtest/simtest-cov.sh
+++ b/scripts/simtest/simtest-cov.sh
@@ -17,7 +17,7 @@ root_dir=$(git rev-parse --show-toplevel)
 export SIMTEST_STATIC_INIT_MOVE=$root_dir"/examples/move/basics"
 
 #TOOLCHAIN=$(rustup show active-toolchain | cut -d ' ' -f 1)
-TOOLCHAIN=nightly
+TOOLCHAIN=nightly-x86_64-unknown-linux-gnu
 LLVM_PROFDATA="$HOME/.rustup/toolchains/$TOOLCHAIN/lib/rustlib/x86_64-unknown-linux-gnu/bin/llvm-profdata"
 
 echo "Computing simtest code coverage."