diff --git a/build-python.sh b/build-python.sh
index 850a5a26a38..cfec5c7b864 100755
--- a/build-python.sh
+++ b/build-python.sh
@@ -370,7 +370,7 @@ if test "${INSTALL}" = true; then
     fi
     # ref for use of '--find-links': https://stackoverflow.com/a/52481267/3986677
     pip install \
-        ${PIP_INSTALL_ARGS:+ -o "PIP_INSTALL_ARGS"} \
+        ${PIP_INSTALL_ARGS:+ -o "$PIP_INSTALL_ARGS"} \
         --force-reinstall \
         --no-cache-dir \
         --no-deps \