diff --git a/ChangeLog b/ChangeLog
index 1553c73cd..772337cf2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -82,6 +82,7 @@
    'burndown' charts.
 
 # Tracked Bugs, sorted by ID.
+ + Fixed bug #403, which disambiguates certain commands involving numbers.
  + Fixed bug #475, which allowed a blank annotation command to be entered
    (thanks to Andreas Kalex).
  + Fixed bug #511, which caused display problem on Cygwin when colored output
diff --git a/src/Arguments.cpp b/src/Arguments.cpp
index 1fcfb0291..38f88ab68 100644
--- a/src/Arguments.cpp
+++ b/src/Arguments.cpp
@@ -1583,6 +1583,7 @@ Arguments Arguments::extract_modifications ()
                arg->_third == "attr"  ||
                arg->_third == "subst" ||
                arg->_third == "op"    ||
+               arg->_third == "exp"   ||
                arg->_third == "word")
       {
         // "limit" is special - it is recognized but not included in filters.
@@ -1603,12 +1604,6 @@ Arguments Arguments::extract_modifications ()
                 + arg->_first
                 + "' is not allowed when modifiying a task.";
 
-        // TODO Really?
-        else if (arg->_third == "exp")
-          throw std::string ("An expression '")
-                + arg->_first
-                + "' is not allowed when modifiying a task.";
-
         else if (arg->_third == "id")
           throw std::string ("A task id cannot be modified.");