diff --git a/.circleci/defaults.sh b/.circleci/defaults.sh
index c7036a69..a9a56b74 100755
--- a/.circleci/defaults.sh
+++ b/.circleci/defaults.sh
@@ -23,7 +23,7 @@ CI_MAKE_NPROC=8
 REMOTE_MAKE_NPROC=4
 
 # verilator version
-VERILATOR_VERSION=v4.212
+VERILATOR_VERSION=v4.034
 
 # remote variables
 REMOTE_PREFIX=$CI_DIR/$CIRCLE_PROJECT_REPONAME-$CIRCLE_BRANCH
diff --git a/project/build.properties b/project/build.properties
index 10fd9eee..dbae93bc 100644
--- a/project/build.properties
+++ b/project/build.properties
@@ -1 +1 @@
-sbt.version=1.5.5
+sbt.version=1.4.9
diff --git a/scripts/centos-req.sh b/scripts/centos-req.sh
index 48fb398c..8c7ac3a0 100755
--- a/scripts/centos-req.sh
+++ b/scripts/centos-req.sh
@@ -29,5 +29,5 @@ sudo yum install -y python
 # install verilator
 git clone http://git.veripool.org/git/verilator
 cd verilator
-git checkout v4.212
+git checkout v4.034
 autoconf && ./configure && make -j$(nproc) && sudo make install
diff --git a/scripts/ubuntu-req.sh b/scripts/ubuntu-req.sh
index 898386e8..ff5fe3ad 100755
--- a/scripts/ubuntu-req.sh
+++ b/scripts/ubuntu-req.sh
@@ -29,5 +29,5 @@ sudo apt-get install git -y
 sudo apt-get install -y autoconf
 git clone http://git.veripool.org/git/verilator
 cd verilator
-git checkout v4.212
+git checkout v4.034
 autoconf && ./configure && make -j$(nproc) && sudo make install