diff --git a/graalpython/lib-graalpython/patches/metadata.toml b/graalpython/lib-graalpython/patches/metadata.toml
index 0c326ce5e6..04daa09fef 100644
--- a/graalpython/lib-graalpython/patches/metadata.toml
+++ b/graalpython/lib-graalpython/patches/metadata.toml
@@ -413,6 +413,10 @@ dist-type = 'sdist'
 version = '1.22.1'
 url = 'https://github.com/microsoft/onnxruntime/archive/refs/tags/v1.22.1.tar.gz'
 
+[[optree.rules]]
+patch = 'optree.patch'
+license = 'Apache-2.0'
+
 [[orjson.rules]]
 version = '== 3.9.7'
 patch = 'orjson-3.9.7.patch'
@@ -691,10 +695,15 @@ patch = 'pythran-0.15.patch'
 license = 'BSD-3-Clause'
 
 [[pythran.rules]]
-version = '>= 0.16'
+version = '>= 0.16, < 0.18.1'
 patch = 'pythran-0.16.patch'
 license = 'BSD-3-Clause'
 
+[[pythran.rules]]
+version = '== 0.18.1'
+patch = 'pythran-0.18.1.patch'
+license = 'BSD-3-Clause'
+
 [[pyzmq.rules]]
 version = '< 26'
 install-priority = 0
diff --git a/graalpython/lib-graalpython/patches/optree.patch b/graalpython/lib-graalpython/patches/optree.patch
new file mode 100644
index 0000000000..c41a0bf4ad
--- /dev/null
+++ b/graalpython/lib-graalpython/patches/optree.patch
@@ -0,0 +1,13 @@
+diff --git a/include/optree/pymacros.h b/include/optree/pymacros.h
+index 7f2ac9a..ecb6faf 100644
+--- a/include/optree/pymacros.h
++++ b/include/optree/pymacros.h
+@@ -52,7 +52,7 @@ namespace py = pybind11;
+ #    define Py_IsFalse(x) Py_Is((x), Py_False)
+ #endif
+ 
+-inline constexpr Py_ALWAYS_INLINE bool Py_IsConstant(PyObject *x) noexcept {
++inline Py_ALWAYS_INLINE bool Py_IsConstant(PyObject *x) noexcept {
+     return Py_IsNone(x) || Py_IsTrue(x) || Py_IsFalse(x);
+ }
+ #define Py_IsConstant(x) Py_IsConstant(x)
diff --git a/graalpython/lib-graalpython/patches/pythran-0.18.1.patch b/graalpython/lib-graalpython/patches/pythran-0.18.1.patch
new file mode 100644
index 0000000000..a6657e2330
--- /dev/null
+++ b/graalpython/lib-graalpython/patches/pythran-0.18.1.patch
@@ -0,0 +1,42 @@
+diff --git a/pythran/pythonic/python/core.hpp b/pythran/pythonic/python/core.hpp
+index 86d2f63..050fe21 100644
+--- a/pythran/pythonic/python/core.hpp
++++ b/pythran/pythonic/python/core.hpp
+@@ -50,7 +50,7 @@ PYTHONIC_NS_BEGIN
+ namespace python
+ {
+ 
+-#ifdef Py_LIMITED_API
++#if defined(Py_LIMITED_API) || defined(GRAALVM_PYTHON)
+ 
+   struct ByteHolder {
+     PyObject *holder;
+diff --git a/pythran/pythonic/types/str.hpp b/pythran/pythonic/types/str.hpp
+index a7dd51a..09fdd59 100644
+--- a/pythran/pythonic/types/str.hpp
++++ b/pythran/pythonic/types/str.hpp
+@@ -732,7 +732,7 @@ namespace std
+   }())
+ #else
+ #ifndef PyString_Check
+-#define PyString_Check(x) (PyUnicode_Check(x) && PyUnicode_IS_COMPACT_ASCII(x))
++#define PyString_Check(x) PyUnicode_Check(x)
+ #endif
+ #endif
+ 
+diff --git a/pythran/tables.py b/pythran/tables.py
+index a9f5712..5a0dff2 100644
+--- a/pythran/tables.py
++++ b/pythran/tables.py
+@@ -4633,7 +4633,10 @@ def save_arguments(module_name, elements):
+             # some function are actually forward function, detect those
+             # and accept to use our description instead.
+             if looks_like_a_forward_function(spec):
+-                assert signature.args.args, "{} require an explicit description".format(elem)
++                # GraalPy change: we have signatures for more builtins than
++                # CPython and this trips up on type constructors like `dict` or
++                # `BaseException`.
++                # assert signature.args.args, "{} require an explicit description".format(elem)
+                 continue
+ 
+             args = [ast.Name(arg, ast.Param(), None, None)