diff --git a/bin/wally-tool-chain-install.sh b/bin/wally-tool-chain-install.sh
index 2c6d5851..138104c7 100755
--- a/bin/wally-tool-chain-install.sh
+++ b/bin/wally-tool-chain-install.sh
@@ -115,9 +115,12 @@ opam install sail -y
 eval $(opam config env)
 git clone https://github.com/riscv/sail-riscv.git
 cd sail-riscv
+# Current bug in Sail - use hash that works for Wally
+#   (may remove later if Sail is ever fixed)
+git checkout 4d05aa1698a0003a4f6f99e1380c743711c32052
 make -j ${NUM_THREADS}
-ARCH=RV32 make
-ARCH=RV64 make
+ARCH=RV32 make -j ${NUM_THREADS}
+ARCH=RV64 make -j ${NUM_THREADS}
 ln -sf $RISCV/sail-riscv/c_emulator/riscv_sim_RV64 /usr/bin/riscv_sim_RV64
 ln -sf $RISCV/sail-riscv/c_emulator/riscv_sim_RV32 /usr/bin/riscv_sim_RV32