diff --git a/CHANGES.txt b/CHANGES.txt
index cfca07fa..a76fbeae 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -5,6 +5,10 @@ TradeDangerous, Copyright (C) Oliver "kfsone" Smith, July 2014
 v6.18.3 Apr 19 2015
 . (kfsone) Added "--shorten" (requires --to)
         Will show routes with less hops if they produces a better gpt
+. (kfsone) "import" maddavo plugin:
+        - Added sanity checking of timestamps during System.csv import
+          (there was a new system in mad's data with an apostrophe in the
+           modified timestamp)
 + (kfsone) ~310 new systems
 
 v6.18.2 Apr 18 2015
diff --git a/plugins/maddavo_plug.py b/plugins/maddavo_plug.py
index a5393173..1672647c 100644
--- a/plugins/maddavo_plug.py
+++ b/plugins/maddavo_plug.py
@@ -274,6 +274,7 @@ def import_systems(self):
         """
 
         tdb, tdenv = self.tdb, self.tdenv
+        dateTimeRe = re.compile(r'\s*(\d{4}-\d{2}-\d{2}[ T]\d{2}:\d{2}:\d{2})')
 
         stream = self.csv_system_rows(SYSTEMS_URL, "Systems")
         for sysName, system, values in stream:
@@ -287,6 +288,13 @@ def import_systems(self):
                 self.modSystems += 1
                 continue
 
+            # Clean up the modified stamp
+            m = dateTimeRe.match(modified)
+            if not m:
+                tdenv.WARN("{} has invalid 'modified': {}", sysName, modified)
+                continue
+            modified = m.group(1)
+
             x, y, z = float(values[1]), float(values[2]), float(values[3])
             if not system:
                 tdb.addLocalSystem(