diff --git a/Project.toml b/Project.toml
index 0c04fb78..c376eb5a 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "BSeries"
 uuid = "ebb8d67c-85b4-416c-b05f-5f409e808f32"
 authors = ["Hendrik Ranocha <mail@ranocha.de> and contributors"]
-version = "0.1.63"
+version = "0.1.64"
 
 [deps]
 Combinatorics = "861a8166-3701-5b0c-9a16-15d98fcdc6aa"
@@ -38,7 +38,7 @@ RootedTrees = "2.23"
 SparseArrays = "1"
 SymEngine = "0.8, 0.9.1, 0.10, 0.11, 0.12"
 SymPy = "2"
-SymPyPythonCall = "0.3"
+SymPyPythonCall = "0.3, 0.4"
 Symbolics = "4, 5"
 julia = "1.6"
 
diff --git a/docs/Project.toml b/docs/Project.toml
index f50f779a..d96fa54a 100644
--- a/docs/Project.toml
+++ b/docs/Project.toml
@@ -19,7 +19,7 @@ Plots = "1"
 PyCall = "1"
 StaticArrays = "1"
 SymEngine = "0.8, 0.9.1, 0.10, 0.11, 0.12"
-SymPyPythonCall = "0.3"
+SymPyPythonCall = "0.3, 0.4"
 Symbolics = "3, 4, 5"
 
 [preferences.OrdinaryDiffEq]
diff --git a/test/Project.toml b/test/Project.toml
index 00c2c9da..3d1ead23 100644
--- a/test/Project.toml
+++ b/test/Project.toml
@@ -14,5 +14,5 @@ Aqua = "0.8"
 StaticArrays = "1"
 SymEngine = "0.8, 0.9.1, 0.10, 0.11, 0.12"
 SymPy = "2"
-SymPyPythonCall = "0.3"
+SymPyPythonCall = "0.3, 0.4"
 Symbolics = "4, 5"