diff -up xulrunner-7.0.1/mozilla-release/js/src/jsregexpinlines.h.yarr-jit xulrunner-7.0.1/mozilla-release/js/src/jsregexpinlines.h
--- xulrunner-7.0.1/mozilla-release/js/src/jsregexpinlines.h.yarr-jit	2011-09-28 22:24:50.000000000 +0200
+++ xulrunner-7.0.1/mozilla-release/js/src/jsregexpinlines.h	2011-10-11 17:35:10.000000000 +0200
@@ -491,7 +491,9 @@ RegExp::compileHelper(JSContext *cx, JSL
     }
 #endif
 
+#if ENABLE_YARR_JIT
     codeBlock.setFallBack(true);
+#endif
     byteCode = JSC::Yarr::byteCompile(yarrPattern, cx->compartment->regExpAllocator).get();
 
     return true;
diff -up xulrunner-7.0.1/mozilla-release/js/src/yarr/wtfbridge.h.yarr-jit xulrunner-7.0.1/mozilla-release/js/src/yarr/wtfbridge.h
--- xulrunner-7.0.1/mozilla-release/js/src/yarr/wtfbridge.h.yarr-jit	2011-09-28 22:24:52.000000000 +0200
+++ xulrunner-7.0.1/mozilla-release/js/src/yarr/wtfbridge.h	2011-10-11 17:35:10.000000000 +0200
@@ -50,7 +50,9 @@
 #include "jstl.h"
 #include "vm/String.h"
 #include "assembler/wtf/Platform.h"
+#if ENABLE_YARR_JIT
 #include "assembler/jit/ExecutableAllocator.h"
+#endif
 
 namespace JSC { namespace Yarr {
 
@@ -261,6 +263,8 @@ deleteAllValues(Vector<T, N> &v) {
     v.deleteAllValues();
 }
 
+#if ENABLE_YARR_JIT
+
 /*
  * Minimal JSGlobalData. This used by Yarr to get the allocator.
  */
@@ -272,6 +276,8 @@ class JSGlobalData {
      : regexAllocator(regexAllocator) { }
 };
 
+#endif
+
 /*
  * Sentinel value used in Yarr.
  */