diff --git a/integration_tests/list_ops_test.ucg b/integration_tests/list_ops_test.ucg
index c12ef30..915effd 100644
--- a/integration_tests/list_ops_test.ucg
+++ b/integration_tests/list_ops_test.ucg
@@ -8,10 +8,15 @@ let filtrator = macro(item) => {
     },
 };
 
+let boolfiltrator = macro(item) => {
+    result = item < 5,
+};
+
 assert |map mapper.result list1 == [2, 3, 4, 5]|;
 assert |(map mapper.result [1, 2, 3, 4]) == [2, 3, 4, 5]|;
 assert |map mapper.result [1, 2, 3, 4] == [2, 3, 4, 5]|;
 
 assert |filter filtrator.result list2 == ["foo", "foo"]|;
 assert |(filter filtrator.result ["foo", "bar", "foo", "bar"]) == ["foo", "foo"]|;
-assert |filter filtrator.result ["foo", "bar", "foo", "bar"] == ["foo", "foo"]|;
\ No newline at end of file
+assert |filter filtrator.result ["foo", "bar", "foo", "bar"] == ["foo", "foo"]|;
+assert |filter boolfiltrator.result [1, 2, 3, 4, 5, 6, 7] == [1, 2, 3, 4]|;
\ No newline at end of file
diff --git a/src/build/mod.rs b/src/build/mod.rs
index 467ccba..0e19110 100644
--- a/src/build/mod.rs
+++ b/src/build/mod.rs
@@ -1151,8 +1151,8 @@ impl<'a> Builder<'a> {
         let mac = &def.mac;
         if let &Val::Macro(ref macdef) = try!(self.lookup_selector(&mac.sel)).as_ref() {
             let mut out = Vec::new();
-            for expr in l.iter() {
-                let argvals = vec![expr.clone()];
+            for item in l.iter() {
+                let argvals = vec![item.clone()];
                 let fields = try!(macdef.eval(
                     self.root.clone(),
                     self.assets.clone(),
@@ -1168,8 +1168,11 @@ impl<'a> Builder<'a> {
                             if let &Val::Empty = v.as_ref() {
                                 // noop
                                 continue;
+                            } else if let &Val::Boolean(false) = v.as_ref() {
+                                // noop
+                                continue;
                             }
-                            out.push(v.clone());
+                            out.push(item.clone());
                         }
                     }
                 }
@@ -1225,9 +1228,11 @@ impl<'a> Builder<'a> {
         } else {
             // record an assertion type-failure result.
             let msg = format!(
-                "TYPE FAIL - '{}' at line: {} column: {}\n",
-                expr, tok.pos.line, tok.pos.column
+                "TYPE FAIL - '{}' Expected Boolean got {} at line: {} column: {}\n",
+                expr, ok, tok.pos.line, tok.pos.column
             );
+            self.assert_collector.failures.push_str(&msg);
+            self.assert_collector.success = false;
             self.assert_collector.summary.push_str(&msg);
         }
         Ok(ok)