diff --git a/requirements.txt b/requirements.txt
index b153308..5f260e4 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,5 @@
-pandas==0.12.0
-shapely==1.2.18
-fiona==1.0.1
-descartes==1.0
+pandas>=0.12.0
+shapely>=1.2.18
+fiona>=1.0.1
+descartes>=1.0
+pyproj>=1.9.3
diff --git a/setup.py b/setup.py
index 51736f3..0bcaf07 100644
--- a/setup.py
+++ b/setup.py
@@ -82,5 +82,5 @@ setup(name='geopandas',
       url='http://geopandas.org',
       long_description=LONG_DESCRIPTION,
       packages=['geopandas'],
-      install_requires=['pandas', 'shapely', 'fiona', 'descartes'],
+      install_requires=['pandas', 'shapely', 'fiona', 'descartes', 'pyproj'],
 )