diff --git a/script/install_PETSC.sh b/script/install_PETSC.sh
index 6a0593492032a1139eb19ff69e1ae847531efd2c..0d59bf1fa53758b3e505258f9fcd9e9db1cb3959 100755
--- a/script/install_PETSC.sh
+++ b/script/install_PETSC.sh
@@ -2,8 +2,8 @@
 
 # check if the directory $1/PETSC exist
 
-CXX=$3
-CC=$4
+CXX=$4
+CC=$3
 F77=$5
 FC=$6