diff --git a/ChangeLog b/ChangeLog
index 89378d25a8..203d0f8d3f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -6,6 +6,7 @@
             Fix irregular timing on Espruino boards with clock crystal (inc rev 1v4)
             Sort out 'Number()' constructor not being picky enough - parseFloat now parses 'Infinity' (Fix #325, mostly fix #322)
             Stop iterator in FOR loop being called once more after a break
+            Fix bug allObjects found with iterating over undefined
 
      1v70 : Make pipe remove its drain/close listeners. Stops out of memory for repeated piping.
             Fix parseInt for values too large to go in an int (#406)
diff --git a/README.md b/README.md
index aa00dddb9d..13f30d6af3 100644
--- a/README.md
+++ b/README.md
@@ -66,7 +66,7 @@ If you are a board manufacturer interested in getting your board officially supp
 * [Espruino Board](http://www.espruino.com/EspruinoBoard) - great support.
 * Linux - WORKING
 * STM32VLDISCOVERY - WORKING - limited memory so some features removed
-* STM32F3DISCOVERY - WORKING
+* STM32F3DISCOVERY - setWatch is broken (issue #183)
 * STM32F4DISCOVERY - WORKING
 * STM32F401CDISCOVERY - appears WORKING, but very little testing done
 * STM32F429IDISCOVERY - WORKING over serial (A9/A10). No USB and no LCD support
@@ -78,7 +78,7 @@ If you are a board manufacturer interested in getting your board officially supp
 * Raspberry Pi - WORKING - GPIO via filesystem (no SPI or I2C)
 * Sony SmartWatch - NOT WORKING - USB VCP support for F2 still needed
 * MBed platforms - have not worked for a while - full hardware wrapper still required
-* ARDUINOMEGA2560 - has never worked
+* ARDUINOMEGA2560 - compiles, but has never worked. Almost certainly due to ints being 16 bits.
 * LC-TECH STM32F103RBT6 - WORKING, but with some issues (LED inverted logic, BTN needs pullup to work)
 
 
diff --git a/src/jsparse.c b/src/jsparse.c
index 9be3be3190..089de9aef6 100644
--- a/src/jsparse.c
+++ b/src/jsparse.c
@@ -1805,60 +1805,62 @@ NO_INLINE JsVar *jspeStatementFor() {
     execInfo.execute &= (JsExecFlags)~EXEC_IN_LOOP;
     JSP_RESTORE_EXECUTE();
 
-    if (jsvIsIterable(array)) {
-      JsvIsInternalChecker checkerFunction = jsvGetInternalFunctionCheckerFor(array);
-      JsVar *foundPrototype = 0;
-
-      JsvIterator it;
-      jsvIteratorNew(&it, array);
-      bool hasHadBreak = false;
-      while (JSP_SHOULD_EXECUTE && jsvIteratorHasElement(&it) && !hasHadBreak) {
-          JsVar *loopIndexVar = jsvIteratorGetKey(&it);
-          bool ignore = false;
-          if (checkerFunction && checkerFunction(loopIndexVar)) {
-            ignore = true;
-            if (jsvIsString(loopIndexVar) &&
-                jsvIsStringEqual(loopIndexVar, JSPARSE_INHERITS_VAR))
-              foundPrototype = jsvSkipName(loopIndexVar);
-          }
-          if (!ignore) {
-            JsVar *indexValue = jsvIsName(loopIndexVar) ?
-                                  jsvCopyNameOnly(loopIndexVar, false/*no copy children*/, false/*not a name*/) :
-                                  loopIndexVar;
-            if (indexValue) { // could be out of memory
-              assert(!jsvIsName(indexValue) && jsvGetRefs(indexValue)==0);
-              jsvSetValueOfName(forStatement, indexValue);
-              if (indexValue!=loopIndexVar) jsvUnLock(indexValue);
+    if (JSP_SHOULD_EXECUTE) {
+      if (jsvIsIterable(array)) {
+        JsvIsInternalChecker checkerFunction = jsvGetInternalFunctionCheckerFor(array);
+        JsVar *foundPrototype = 0;
+
+        JsvIterator it;
+        jsvIteratorNew(&it, array);
+        bool hasHadBreak = false;
+        while (JSP_SHOULD_EXECUTE && jsvIteratorHasElement(&it) && !hasHadBreak) {
+            JsVar *loopIndexVar = jsvIteratorGetKey(&it);
+            bool ignore = false;
+            if (checkerFunction && checkerFunction(loopIndexVar)) {
+              ignore = true;
+              if (jsvIsString(loopIndexVar) &&
+                  jsvIsStringEqual(loopIndexVar, JSPARSE_INHERITS_VAR))
+                foundPrototype = jsvSkipName(loopIndexVar);
+            }
+            if (!ignore) {
+              JsVar *indexValue = jsvIsName(loopIndexVar) ?
+                                    jsvCopyNameOnly(loopIndexVar, false/*no copy children*/, false/*not a name*/) :
+                                    loopIndexVar;
+              if (indexValue) { // could be out of memory
+                assert(!jsvIsName(indexValue) && jsvGetRefs(indexValue)==0);
+                jsvSetValueOfName(forStatement, indexValue);
+                if (indexValue!=loopIndexVar) jsvUnLock(indexValue);
+
+                jsvIteratorNext(&it);
+
+                jslSeekToP(execInfo.lex, &forBodyStart);
+                execInfo.execute |= EXEC_IN_LOOP;
+                jsvUnLock(jspeBlockOrStatement());
+                execInfo.execute &= (JsExecFlags)~EXEC_IN_LOOP;
   
-              jsvIteratorNext(&it);
- 
-              jslSeekToP(execInfo.lex, &forBodyStart);
-              execInfo.execute |= EXEC_IN_LOOP;
-              jsvUnLock(jspeBlockOrStatement());
-              execInfo.execute &= (JsExecFlags)~EXEC_IN_LOOP;
-
-              if (execInfo.execute == EXEC_CONTINUE)
-                execInfo.execute = EXEC_YES;
-              if (execInfo.execute == EXEC_BREAK) {
-                execInfo.execute = EXEC_YES;
-                hasHadBreak = true;
+                if (execInfo.execute == EXEC_CONTINUE)
+                  execInfo.execute = EXEC_YES;
+                if (execInfo.execute == EXEC_BREAK) {
+                  execInfo.execute = EXEC_YES;
+                  hasHadBreak = true;
+                }
               }
+            } else
+              jsvIteratorNext(&it);
+            jsvUnLock(loopIndexVar);
+
+            if (!jsvIteratorHasElement(&it) && foundPrototype) {
+              jsvIteratorFree(&it);
+              jsvIteratorNew(&it, foundPrototype);
+              jsvUnLock(foundPrototype);
+              foundPrototype = 0;
             }
-          } else
-            jsvIteratorNext(&it);
-          jsvUnLock(loopIndexVar);
-
-          if (!jsvIteratorHasElement(&it) && foundPrototype) {
-            jsvIteratorFree(&it);
-            jsvIteratorNew(&it, foundPrototype);
-            jsvUnLock(foundPrototype);
-            foundPrototype = 0;
-          }
+        }
+        assert(!foundPrototype);
+        jsvIteratorFree(&it);
+      } else {
+        jsExceptionHere(JSET_ERROR, "FOR loop can only iterate over Arrays, Strings or Objects, not %t", array);
       }
-      assert(!foundPrototype);
-      jsvIteratorFree(&it);
-    } else {
-      jsExceptionHere(JSET_ERROR, "FOR loop can only iterate over Arrays, Strings or Objects, not %t", array);
     }
     jslSeekToP(execInfo.lex, &forBodyEnd);
     jslCharPosFree(&forBodyStart);
diff --git a/tests/test_for_noexec.js b/tests/test_for_noexec.js
new file mode 100644
index 0000000000..99740f98ed
--- /dev/null
+++ b/tests/test_for_noexec.js
@@ -0,0 +1,5 @@
+//http://forum.espruino.com/conversations/256957/#comment11907195
+var c = undefined;
+if (c) for (var i in c) ;
+for (var i in c) ;
+result = 1;