diff --git a/assets/monitor.js b/assets/monitor.js
--- a/assets/monitor.js
+++ b/assets/monitor.js
@@ -158,6 +158,9 @@
 
                 data[i].push([time, series[i].fn(stats, time,
                                                  prev_stats, prev_time)]);
+
+                // the data may arrive out-of-order, so sort by time stamp first
+                data[i].sort(function (a, b) { return a[0] - b[0]; });
             }
 
             // zip legends with data
diff --git a/ekg.cabal b/ekg.cabal
--- a/ekg.cabal
+++ b/ekg.cabal
@@ -1,5 +1,5 @@
 name:                ekg
-version:             0.4.0.8
+version:             0.4.0.9
 synopsis:            Remote monitoring of processes
 description:
   This library lets you remotely monitor a running process over HTTP.
@@ -23,6 +23,7 @@
                      assets/bootstrap-1.4.0.css
                      examples/Basic.hs CHANGES.md
 cabal-version:       >= 1.8
+tested-with:         GHC == 7.10.1, GHC == 7.8.4, GHC == 7.6.3
 
 library
   exposed-modules:
@@ -37,7 +38,7 @@
     System.Remote.Snap
 
   build-depends:
-    aeson < 0.11,
+    aeson < 0.12,
     base >= 4.5 && < 4.9,
     bytestring < 1.0,
     ekg-core >= 0.1 && < 0.2,