diff --git a/setup.py b/setup.py
index 102e87fb0..3b3a959cf 100755
--- a/setup.py
+++ b/setup.py
@@ -60,7 +60,7 @@
                         'psutil>=3.3.0',
                         'intervaltree>=3.0',
                         'sortedcontainers',
-                        'unicorn>=1.0.2rc1', # see unicorn-engine/unicorn#1100, unicorn-engine/unicorn#1170
+                        'unicorn>=1.0.2rc1,<1.0.2rc4', # see unicorn-engine/unicorn#1100, unicorn-engine/unicorn#1170, Gallopsled/pwntools#1538
 ]
 
 # Check that the user has installed the Python development headers