diff --git a/src/Filter.cpp b/src/Filter.cpp
index 1ecce6124..af0dc063a 100644
--- a/src/Filter.cpp
+++ b/src/Filter.cpp
@@ -83,6 +83,7 @@ void Filter::subset (const std::vector <Task>& input, std::vector <Task>& output
   if (filterExpr.length ())
   {
     Eval eval;
+    eval.ambiguity (false);
     eval.addSource (namedDates);
     eval.addSource (domSource);
 
@@ -90,7 +91,6 @@ void Filter::subset (const std::vector <Task>& input, std::vector <Task>& output
     // it is mostly noise.
     eval.debug (context.config.getBoolean ("debug"));
     eval.compileExpression (filterExpr);
-    eval.ambiguity (false);
     eval.debug (false);
 
     std::vector <Task>::const_iterator task;
@@ -136,6 +136,7 @@ void Filter::subset (std::vector <Task>& output)
     _startCount = (int) pending.size ();
 
     Eval eval;
+    eval.ambiguity (false);
     eval.addSource (namedDates);
     eval.addSource (domSource);
 
@@ -143,7 +144,6 @@ void Filter::subset (std::vector <Task>& output)
     // it is mostly noise.
     eval.debug (context.config.getBoolean ("debug"));
     eval.compileExpression (filterExpr);
-    eval.ambiguity (false);
     eval.debug (false);
 
     output.clear ();