diff --git a/src/node_idle_watcher.cc b/src/node_idle_watcher.cc
index fc09953e69..a1fb202dac 100644
--- a/src/node_idle_watcher.cc
+++ b/src/node_idle_watcher.cc
@@ -11,7 +11,7 @@ namespace node {
 using namespace v8;
 
 Persistent<FunctionTemplate> IdleWatcher::constructor_template;
-Persistent<String> callback_symbol;
+static Persistent<String> callback_symbol;
 
 void IdleWatcher::Initialize(Handle<Object> target) {
   HandleScope scope;
diff --git a/src/node_io_watcher.cc b/src/node_io_watcher.cc
index 4a2d9378d9..61e49f6bc5 100644
--- a/src/node_io_watcher.cc
+++ b/src/node_io_watcher.cc
@@ -11,7 +11,7 @@ namespace node {
 using namespace v8;
 
 Persistent<FunctionTemplate> IOWatcher::constructor_template;
-Persistent<String> callback_symbol;
+static Persistent<String> callback_symbol;
 
 void IOWatcher::Initialize(Handle<Object> target) {
   HandleScope scope;