diff --git a/script/install_PETSC.sh b/script/install_PETSC.sh
index 062be00c080a69f90eadd9a3847e45b26ca084ff..225b93c8012d5d7fdc0cf0c9e2e6c8bc9f9723ef 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