diff --git a/SConstruct b/SConstruct
index 9faeb71..c382e2b 100644
--- a/SConstruct
+++ b/SConstruct
@@ -163,6 +163,7 @@ add_option( "release" , "release build" , 0 , True )
 add_option( "static" , "fully static build" , 0 , False )
 add_option( "static-libstdc++" , "statically link libstdc++" , 0 , False )
 add_option( "lto", "enable link time optimizations (experimental, except with MSVC)" , 0 , True )
+add_option( "disable-declspec-thread", "don't use __declspec(thread) on Windows", 0, True)
 
 # base compile flags
 add_option( "64" , "whether to force 64 bit" , 0 , True , "force64" )
@@ -1194,6 +1195,51 @@ def doConfigure(myenv):
     if linux:
         AddToCCFLAGSIfSupported(myenv, "-fno-builtin-memcmp")
 
+    # When using msvc, check for support for __declspec(thread), unless we have been asked
+    # explicitly not to use it. For other compilers, see if __thread works.
+    if using_msvc():
+        haveDeclSpecThread = False
+        if not has_option("disable-declspec-thread"):
+            def CheckDeclspecThread(context):
+                test_body = """
+                __declspec( thread ) int tsp_int;
+                int main(int argc, char* argv[]) {
+                    tsp_int = argc;
+                    return 0;
+                }
+                """
+                context.Message('Checking for __declspec(thread)... ')
+                ret = context.TryLink(textwrap.dedent(test_body), ".cpp")
+                context.Result(ret)
+                return ret
+            conf = Configure(myenv, help=False, custom_tests = {
+                'CheckDeclspecThread' : CheckDeclspecThread,
+            })
+            haveDeclSpecThread = conf.CheckDeclspecThread()
+            conf.Finish()
+        if haveDeclSpecThread:
+            myenv.Append(CPPDEFINES=['MONGO_HAVE___DECLSPEC_THREAD'])
+    else:
+        def CheckUUThread(context):
+            test_body = """
+            __thread int tsp_int;
+            int main(int argc, char* argv[]) {
+                tsp_int = argc;
+                return 0;
+            }
+            """
+            context.Message('Checking for __thread... ')
+            ret = context.TryLink(textwrap.dedent(test_body), ".cpp")
+            context.Result(ret)
+            return ret
+        conf = Configure(myenv, help=False, custom_tests = {
+            'CheckUUThread' : CheckUUThread,
+        })
+        haveUUThread = conf.CheckUUThread()
+        conf.Finish()
+        if haveUUThread:
+            myenv.Append(CPPDEFINES=['MONGO_HAVE___THREAD'])
+
     conf = Configure(myenv)
 
     if use_system_version_of_library("pcre"):
diff --git a/src/mongo/db/storage/record.cpp b/src/mongo/db/storage/record.cpp
index 211ceaf..b3ecdf8 100644
--- a/src/mongo/db/storage/record.cpp
+++ b/src/mongo/db/storage/record.cpp
@@ -383,12 +383,12 @@ namespace mongo {
 
     
     // These need to be outside the ps namespace due to the way they are defined
-#if defined(__linux__) && defined(__GNUC__)
+#if defined(MONGO_HAVE___THREAD)
     __thread ps::PointerTable::Data _pointerTableData;
     ps::PointerTable::Data* ps::PointerTable::getData() { 
         return &_pointerTableData; 
     }
-#elif defined(_WIN32)
+#elif defined(MONGO_HAVE___DECLSPEC_THREAD)
     __declspec( thread ) ps::PointerTable::Data _pointerTableData;
     ps::PointerTable::Data* ps::PointerTable::getData() { 
         return &_pointerTableData; 
diff --git a/src/mongo/util/concurrency/threadlocal.h b/src/mongo/util/concurrency/threadlocal.h
index 4929833..a6f84ac 100644
--- a/src/mongo/util/concurrency/threadlocal.h
+++ b/src/mongo/util/concurrency/threadlocal.h
@@ -74,7 +74,7 @@ namespace mongo {
        a combination here, with the assumption that reset's are infrequent, so that 
        get's are fast.
     */
-#if defined(_WIN32) || (defined(__GNUC__) && defined(__linux__))
+#if defined(MONGO_HAVE___THREAD) || defined(MONGO_HAVE___DECLSPEC_THREAD)
         
     template< class T >
     struct TSP {
@@ -90,7 +90,7 @@ namespace mongo {
         }
     };
 
-# if defined(_WIN32)
+# if defined(MONGO_HAVE___DECLSPEC_THREAD)
 
 #  define TSP_DECLARE(T,p) extern TSP<T> p;
 
@@ -117,7 +117,7 @@ namespace mongo {
     TSP<T> p;
 # endif
 
-#elif defined(__APPLE__)
+#elif defined(_POSIX_THREADS) && (_POSIX_THREADS >= 0)
     template< class T>
     struct TSP {
         pthread_key_t _key;