diff --git a/src/Task.cpp b/src/Task.cpp
index 4dd3c8ee3..db5086c50 100644
--- a/src/Task.cpp
+++ b/src/Task.cpp
@@ -952,6 +952,15 @@ void Task::validate () const
   if (has ("wait") &&
       getStatus () == Task::recurring)
     throw std::string (STRING_TASK_VALID_WAIT_RECUR);
+
+  if (has ("priority"))
+  {
+    std::string priority - get ("priority");
+    if (priority != "H" &&
+        priority != "M" &&
+        priority != "L")
+      throw format (STRING_TASK_VALID_PRIORITY, priority);
+  }
 }
 
 ////////////////////////////////////////////////////////////////////////////////
diff --git a/src/en-US.h b/src/en-US.h
index 0bb1ee4e0..998a02f92 100644
--- a/src/en-US.h
+++ b/src/en-US.h
@@ -420,6 +420,7 @@
 #define STRING_TASK_VALID_UNTIL      "You cannot specify an until date for a non-recurring task."
 #define STRING_TASK_VALID_RECUR      "A recurrence value must be valid."
 #define STRING_TASK_VALID_WAIT_RECUR "You cannot create a task that is both waiting and recurring."
+#define STRING_TASK_VALID_PRIORITY   "Priority values may be 'H', 'M' or 'L', not '{1}'."
 
 
 // Taskmod