diff --git a/debian/clean b/debian/clean
new file mode 100644
index 0000000000000000000000000000000000000000..36aa74c66736a2f97a2ea8777dc43e85310d6354
--- /dev/null
+++ b/debian/clean
@@ -0,0 +1 @@
+.eggs/README.txt
diff --git a/debian/control b/debian/control
index da13aec54ecaab4b6e03e82c2ce2aa740446ba0e..d2f4019cd11cf749eb6310a71b217500e8415b4b 100644
--- a/debian/control
+++ b/debian/control
@@ -6,7 +6,7 @@ Testsuite: autopkgtest-pkg-python
 Priority: optional
 Build-Depends: debhelper-compat (= 13),
                dh-sequence-python3,
-               cython3-legacy,
+               cython3,
                python3-all-dev,
                python3-setuptools,
                python3-ruamel.yaml,
diff --git a/debian/patches/cython3.patch b/debian/patches/cython3.patch
new file mode 100644
index 0000000000000000000000000000000000000000..d298a79421583670ea27d73650f6ee7297fa0b92
--- /dev/null
+++ b/debian/patches/cython3.patch
@@ -0,0 +1,21 @@
+--- a/srsly/msgpack/_unpacker.pyx
++++ b/srsly/msgpack/_unpacker.pyx
+@@ -10,7 +10,6 @@
+ from libc.stdlib cimport *
+ from libc.string cimport *
+ from libc.limits cimport *
+-ctypedef unsigned long long uint64_t
+ 
+ from .exceptions import (
+     BufferFull,
+--- a/setup.cfg
++++ b/setup.cfg
+@@ -31,7 +31,7 @@
+ include_package_data = true
+ python_requires = >=3.6
+ setup_requires =
+-    cython>=0.29.1,<0.30.0
++    cython>=0.29.1
+ install_requires =
+     catalogue>=2.0.3,<2.1.0
+ 
diff --git a/debian/patches/series b/debian/patches/series
index beae86f85f67047bf34d325bb82c6d419208b8cd..680cc985d4bf90d08f42be3831de6d0abd9aa0c2 100644
--- a/debian/patches/series
+++ b/debian/patches/series
@@ -1 +1,2 @@
 unittest-mock.patch
+cython3.patch