diff --git a/Project.toml b/Project.toml
index 35d249d5..d06a9644 100644
--- a/Project.toml
+++ b/Project.toml
@@ -43,7 +43,7 @@ Reexport = "1"
 Setfield = "1"
 SparseArrays = "1.10"
 StaticArrays = "1.5"
-SummationByPartsOperators = "0.5.42"
+SummationByPartsOperators = "0.5.20"
 Triangulate = "2.2"
 WriteVTK = "1.19"
 julia = "1.7"