diff --git a/.circleci/config.yml b/.circleci/config.yml
index 6fba52f..db8d31b 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -25,6 +25,7 @@ jobs:
             # Check whether cache restoration succeeds by checking whether
             # mlir-opt executable exists.
             if [ ! -f llvm-project/build/bin/mlir-opt ]; then
+              export MAKEFLAGS=-j4
               source ONNF/utils/install-mlir.sh
             fi
       - save_cache:
diff --git a/README.md b/README.md
index 19c3d64..af6932e 100644
--- a/README.md
+++ b/README.md
@@ -20,7 +20,7 @@ cmake -G Ninja ../llvm \
    -DLLVM_ENABLE_ASSERTIONS=ON \
    -DLLVM_ENABLE_RTTI=ON
 
-cmake --build . --target
+cmake --build . --target -- ${MAKEFLAGS}
 cmake --build . --target check-mlir
 ```
 
diff --git a/utils/install-mlir.sh b/utils/install-mlir.sh
index d47c37a..39f06ea 100644
--- a/utils/install-mlir.sh
+++ b/utils/install-mlir.sh
@@ -9,5 +9,5 @@ cmake -G Ninja ../llvm \
    -DLLVM_ENABLE_ASSERTIONS=ON \
    -DLLVM_ENABLE_RTTI=ON
 
-cmake --build . --target
+cmake --build . --target -- ${MAKEFLAGS}
 cmake --build . --target check-mlir
\ No newline at end of file