Set version 3.2.
diff --git a/heron/shell/src/python/BUILD b/heron/shell/src/python/BUILD
index 6d5392f..38cedc0 100644
--- a/heron/shell/src/python/BUILD
+++ b/heron/shell/src/python/BUILD
@@ -10,7 +10,7 @@
     ),
     reqs = [
         "requests==2.3.0",
-        "tornado==4.3",
+        "tornado==3.2",
     ],
 )
 
diff --git a/heron/tracker/src/python/BUILD b/heron/tracker/src/python/BUILD
index 59e7f97..3946322 100644
--- a/heron/tracker/src/python/BUILD
+++ b/heron/tracker/src/python/BUILD
@@ -15,7 +15,7 @@
     ],
     reqs = [
         "protobuf==2.5.0",
-        "tornado==4.3",
+        "tornado==3.2",
     ],
 )
 
diff --git a/heron/ui/src/python/BUILD b/heron/ui/src/python/BUILD
index f25ee00..fdcb2d8 100644
--- a/heron/ui/src/python/BUILD
+++ b/heron/ui/src/python/BUILD
@@ -11,7 +11,7 @@
     reqs = [
         "pycrypto==2.6.1",
         "requests==2.3.0",
-        "tornado==4.3",
+        "tornado==3.2",
     ],
 )
 
diff --git a/integration-test/src/python/http_server/BUILD b/integration-test/src/python/http_server/BUILD
index aeaeb4a..f6f65f8 100644
--- a/integration-test/src/python/http_server/BUILD
+++ b/integration-test/src/python/http_server/BUILD
@@ -9,6 +9,6 @@
     ],
     main = "main.py",
     reqs = [
-        "tornado==4.3",
+        "tornado==3.2",
     ],
 )