diff --git a/bin/installdumux.py b/bin/installdumux.py
index cf6d070667facf9012f52d462ba695b0d1727fa0..6fe5f548bc3caeee60b1c08bf28aae93e4b20f14 100755
--- a/bin/installdumux.py
+++ b/bin/installdumux.py
@@ -50,7 +50,7 @@ parser = argparse.ArgumentParser(
 )
 # Optional arguments
 parser.add_argument("--dune-version", default="2.9", help="Dune version to be checked out.")
-parser.add_argument("--dumux-version", default="3.7", help="Dumux version to be checked out.")
+parser.add_argument("--dumux-version", default="3.8", help="Dumux version to be checked out.")
 args = vars(parser.parse_args())
 
 duneBranch = (
diff --git a/bin/installexternal.py b/bin/installexternal.py
index b0fa27e303cfbbc27340405b9c4b8d6f2553a446..394ffe228c8a8faf561d93401291efcf0c8a94d1 100755
--- a/bin/installexternal.py
+++ b/bin/installexternal.py
@@ -215,7 +215,7 @@ options.add_argument(
 
 parser.add_argument("--dune-branch", default="releases/2.9", help="Dune branch to be checked out.")
 parser.add_argument(
-    "--dumux-branch", default="releases/3.7", help="Dumux branch to be checked out."
+    "--dumux-branch", default="releases/3.8", help="Dumux branch to be checked out."
 )
 parser.add_argument("--opm-branch", default="release/2022.10", help="Opm branch to be checked out.")
 parser.add_argument("--mmesh-branch", default="release/1.4", help="Mmesh branch to be checked out.")