diff --git a/requirements.txt b/requirements.txt
index b33f0565ae08959defee9b6674c271947534fd56..55d5ba9466e17d361649fd89f284c5c7c1337986 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,5 @@
-six>=1.10.0,<2.0
-numpy>=1.11.1,<2.0
-nibabel>=2.1,<3.0
-indexed_gzip>=0.3.3,<0.4
+six==1.*
+numpy==1.*
+nibabel==2.*
+indexed_gzip==0.3.*
 wxPython>=3.0.2.0,<4.1