diff --git a/tox.ini b/tox.ini
index 32d71ee68bf7..574c1218025e 100644
--- a/tox.ini
+++ b/tox.ini
@@ -8,7 +8,7 @@ commands =
 deps =
     nose
     unittest2
-    protobuf==3.0.0-alpha1
+    protobuf==3.0.0-alpha-1
 
 [testenv]
 install_command =
@@ -18,7 +18,7 @@ commands =
 deps =
     nose
     unittest2
-    protobuf==3.0.0-alpha1
+    protobuf==3.0.0-alpha-1
 
 [testenv:cover]
 basepython =
@@ -28,7 +28,7 @@ commands =
 deps =
     nose
     unittest2
-    protobuf==3.0.0-alpha1
+    protobuf==3.0.0-alpha-1
     coverage
     nosexcover
 
@@ -64,7 +64,7 @@ deps =
     pep8
     pylint
     unittest2
-    protobuf==3.0.0-alpha1
+    protobuf==3.0.0-alpha-1
 
 [testenv:regression]
 basepython =
@@ -73,7 +73,7 @@ commands =
     {toxinidir}/scripts/run_regression.sh
 deps =
     unittest2
-    protobuf==3.0.0-alpha1
+    protobuf==3.0.0-alpha-1
 
 [testenv:regression3]
 basepython =
@@ -82,4 +82,4 @@ commands =
     {toxinidir}/scripts/run_regression.sh
 deps =
     unittest2
-    protobuf==3.0.0-alpha1
+    protobuf==3.0.0-alpha-1