diff --git a/script/install_PETSC.sh b/script/install_PETSC.sh
index 15f1acee97df4f2aa2c66f1f08f9796f95260659..35be00e4bf0e191d6f697cf9f882151cbfc335de 100755
--- a/script/install_PETSC.sh
+++ b/script/install_PETSC.sh
@@ -33,7 +33,7 @@ function haveProg() {
 if haveProg python2; then
   python_command=python2
 else
-  python_command=python
+  python_command=python3
 fi