diff --git a/setup.py b/setup.py
index <HASH>..<HASH> 100755
--- a/setup.py
+++ b/setup.py
@@ -32,7 +32,7 @@ setup(name="karabo_bridge",
       long_description=read("README.rst"),
       license="BSD-3-Clause",
       install_requires=[
-          'msgpack>=0.5.4',
+          'msgpack==0.5.4',
           'msgpack-numpy',
           'numpy',
           'pyzmq>=17.0.0',
new msgpack version breaks test for now...