diff --git a/scripts/setup-helper-functions.sh b/scripts/setup-helper-functions.sh
index 4f0a11e152fd9..ae4b192f4a092 100644
--- a/scripts/setup-helper-functions.sh
+++ b/scripts/setup-helper-functions.sh
@@ -169,6 +169,6 @@ function cmake_install {
     -DCMAKE_CXX_FLAGS="$COMPILER_FLAGS" \
     -DBUILD_TESTING=OFF \
     "$@"
-  ninja -C "${BINARY_DIR}" install
+  ${SUDO} ninja -C "${BINARY_DIR}" install
 }
 
diff --git a/scripts/setup-ubuntu.sh b/scripts/setup-ubuntu.sh
index 102974b6a3333..83d3e5b3aff8f 100755
--- a/scripts/setup-ubuntu.sh
+++ b/scripts/setup-ubuntu.sh
@@ -16,6 +16,7 @@
 # Minimal setup for Ubuntu 20.04.
 set -eufx -o pipefail
 SCRIPTDIR=$(dirname "${BASH_SOURCE[0]}")
+SUDO=sudo
 source $SCRIPTDIR/setup-helper-functions.sh
 
 # Folly must be built with the same compiler flags so that some low level types