diff --git a/coin/provisioning/qtci-macos-10.12-x86_64/26-p7zip.sh b/coin/provisioning/qtci-macos-10.12-x86_64/26-p7zip.sh
index 15511332..507463f8 100755
--- a/coin/provisioning/qtci-macos-10.12-x86_64/26-p7zip.sh
+++ b/coin/provisioning/qtci-macos-10.12-x86_64/26-p7zip.sh
@@ -4,4 +4,4 @@
 set -ex
 
 brew update
-brew install p7zip
+brew install --build-from-source p7zip
diff --git a/coin/provisioning/qtci-macos-10.13-x86_64/26-p7zip.sh b/coin/provisioning/qtci-macos-10.13-x86_64/26-p7zip.sh
index 15511332..507463f8 100755
--- a/coin/provisioning/qtci-macos-10.13-x86_64/26-p7zip.sh
+++ b/coin/provisioning/qtci-macos-10.13-x86_64/26-p7zip.sh
@@ -4,4 +4,4 @@
 set -ex
 
 brew update
-brew install p7zip
+brew install --build-from-source p7zip