diff --git a/HISTORY.md b/HISTORY.md
index 3fc4b74c..7175d696 100755
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -6,6 +6,9 @@
 * **Notable Fixes:**
 * **Translation Updates:**
 
+### 2019-07-10
+* threads: fixed a glitch when running a generic WHEN hat block with a literal Boolean input 
+
 ## v5.0.3
 * **Notable Change:**
     * CSV-parsing auto-detects the most likely delimiter among comma, semi-colon, pipe and tab
diff --git a/snap.html b/snap.html
index a1336f45..ec39eab3 100755
--- a/snap.html
+++ b/snap.html
@@ -7,7 +7,7 @@
         <script type="text/javascript" src="src/morphic.js?version=2019-07-08"></script>
         <script type="text/javascript" src="src/widgets.js?version=2019-06-27"></script>
         <script type="text/javascript" src="src/blocks.js?version=2019-07-09"></script>
-        <script type="text/javascript" src="src/threads.js?version=2019-07-10"></script>
+        <script type="text/javascript" src="src/threads.js?version=2019-07-15"></script>
         <script type="text/javascript" src="src/objects.js?version=2019-07-08"></script>
         <script type="text/javascript" src="src/gui.js?version=2019-07-10"></script>
         <script type="text/javascript" src="src/paint.js?version=2019-06-27"></script>
diff --git a/src/threads.js b/src/threads.js
index b6be0761..bc79cb82 100644
--- a/src/threads.js
+++ b/src/threads.js
@@ -61,7 +61,7 @@ StageMorph, SpriteMorph, StagePrompterMorph, Note, modules, isString, copy,
 isNil, WatcherMorph, List, ListWatcherMorph, alert, console, TableMorph, Color,
 TableFrameMorph, ColorSlotMorph, isSnapObject, Map, newCanvas, Symbol*/
 
-modules.threads = '2019-July-10';
+modules.threads = '2019-July-15';
 
 var ThreadManager;
 var Process;
@@ -460,7 +460,7 @@ ThreadManager.prototype.doWhen = function (block, receiver, stopIt) {
     // since we're asking for the whole context instead of just the result
     // of the computation, we need to look at the result-context's first
     // input to find out whether the condition is met
-    if (test && test.inputs[0] === true) {
+    if (test === true || (test && test.inputs && test.inputs[0] === true)) {
         this.startProcess(
             block,
             receiver,