diff --git a/ci/build-riscv-tests.sh b/ci/build-riscv-tests.sh
index b88638e80..6be78a45b 100755
--- a/ci/build-riscv-tests.sh
+++ b/ci/build-riscv-tests.sh
@@ -11,7 +11,7 @@ autoconf
 mkdir -p build
 cd build
 ../configure --prefix=$ROOT/tmp/riscv-tests/build
-make isa -j
+make isa -j2
 make install
 
 cd isa
diff --git a/ci/install-fesvr.sh b/ci/install-fesvr.sh
index 31d513912..6e943922e 100755
--- a/ci/install-fesvr.sh
+++ b/ci/install-fesvr.sh
@@ -12,5 +12,5 @@ cd $ROOT/tmp/riscv-fesvr-$RELEASE
 mkdir -p build
 cd build
 ../configure --prefix="$ROOT/tmp"
-make -j
+make -j2
 make install
diff --git a/ci/install-verilator.sh b/ci/install-verilator.sh
index 19b7c4e51..953f92450 100755
--- a/ci/install-verilator.sh
+++ b/ci/install-verilator.sh
@@ -7,7 +7,7 @@ if [ ! -e "$ROOT/tmp/bin/verilator" ]; then
     echo "Installing Verilator"
     wget https://www.veripool.org/ftp/verilator-3.918.tgz
     tar xzf verilator*.t*gz && cd verilator-*
-    autoconf && ./configure --prefix="$ROOT/tmp" && make -j && make test && make install
+    autoconf && ./configure --prefix="$ROOT/tmp" && make -j2 && make test && make install
 else
     echo "Using Verilator from cached directory."
 fi