diff --git a/js/src/jit-test/tests/jaeger/bug642198.js b/js/src/jit-test/tests/jaeger/bug642198.js
new file mode 100644
index 00000000000..dec6e7294f2
--- /dev/null
+++ b/js/src/jit-test/tests/jaeger/bug642198.js
@@ -0,0 +1,9 @@
+
+function test() {
+    for(var e=1.2; true; e=20.2) {
+        if (e > 10)
+            break;
+    }
+}
+test();
+
diff --git a/js/src/methodjit/FrameState.cpp b/js/src/methodjit/FrameState.cpp
index fa2c3a4f847..7dcd19b9af9 100644
--- a/js/src/methodjit/FrameState.cpp
+++ b/js/src/methodjit/FrameState.cpp
@@ -647,7 +647,7 @@ FrameState::syncForBranch(jsbytecode *target, Uses uses)
 
         JS_ASSERT_IF(!fe->isType(JSVAL_TYPE_DOUBLE), fe->type.synced());
         if (!fe->data.synced() && alloc->synced(reg))
-            syncData(fe);
+            syncFe(fe);
 
         if (fe->dataInRegister(reg))
             continue;