diff --git a/js-assembler/runtime-src/baselib-functions.js b/js-assembler/runtime-src/baselib-functions.js
index e22ac93..f0a15aa 100644
--- a/js-assembler/runtime-src/baselib-functions.js
+++ b/js-assembler/runtime-src/baselib-functions.js
@@ -144,8 +144,8 @@
             var oldVal = MACHINE.v;
             var oldArgcount = MACHINE.a;
             var oldProc = MACHINE.p;
-
             var oldErrorHandler = MACHINE.params['currentErrorHandler'];
+
             var afterGoodInvoke = function (MACHINE) { 
                 plt.runtime.PAUSE(
                     function (restart) {
@@ -186,8 +186,15 @@
                 MACHINE.a = oldArgcount;
                 MACHINE.p = oldProc;
                 fail(e);
+
             };
-            MACHINE.trampoline(v.label);
+
+            MACHINE.exclusiveLock.acquire(
+                "js-as-closure",
+                function(releaseLock) {
+                    releaseLock();
+                    MACHINE.trampoline(v.label);
+                });
         };
         return f;
     };
@@ -270,6 +277,7 @@
                 MACHINE.p = oldProc;
                 fail(e);
             };
+
             MACHINE.trampoline(proc.label);
         } else {
             fail(baselib.exceptions.makeExnFail(
diff --git a/js-assembler/runtime-src/runtime.js b/js-assembler/runtime-src/runtime.js
index ff9e4f6..663f4fb 100644
--- a/js-assembler/runtime-src/runtime.js
+++ b/js-assembler/runtime-src/runtime.js
@@ -197,7 +197,7 @@
             this.locked = id;
             onAcquire.call(
                 this,
-                // NOTE: the caller must release the lock or else deadlock.
+                // NOTE: the caller must release the lock or else deadlock!
                 function() {
                     setTimeout(
                         function() {
@@ -441,13 +441,16 @@
     var recomputeMaxNumBouncesBeforeYield;
 
     var scheduleTrampoline = function(MACHINE, f) {
-        setTimeout(
-	    function() { 
- 
-               // FIXME!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
-                return MACHINE.trampoline(f); 
-            },
-	    0);
+        MACHINE.exclusiveLock.acquire(
+            'scheduleTrampoline',
+            function(release) {
+                setTimeout(
+	            function() { 
+                        release();
+                        return MACHINE.trampoline(f); 
+                    },
+	            0);
+            });
     };
 
     // Creates a restarting function, that reschedules f in a context
@@ -486,7 +489,7 @@
     // Make sure to get an exclusive lock before jumping into trampoline.
     // Otherwise, Bad Things will happen.
     //
-    // e.g. machine.lock.acquire(function() { machine.trampoline... machine.lock.release();});
+    // e.g. machine.lock.acquire('id', function(release) { machine.trampoline... release();});
     
     Machine.prototype.trampoline = function(initialJump, noJumpingOff) {
 	var thunk = initialJump;
diff --git a/version.rkt b/version.rkt
index 865b3e0..96261f3 100644
--- a/version.rkt
+++ b/version.rkt
@@ -7,4 +7,4 @@
 (provide version)
 (: version String)
 
-(define version "1.96")
+(define version "1.97")