diff --git a/atom/common/platform_util_linux.cc b/atom/common/platform_util_linux.cc
index 8cfa516038..bf3c3b272b 100644
--- a/atom/common/platform_util_linux.cc
+++ b/atom/common/platform_util_linux.cc
@@ -95,7 +95,7 @@ bool OpenExternal(const GURL& url, bool activate) {
 bool OpenExternal(const GURL& url, bool activate, const OpenExternalCallback& callback) {
   // TODO: Implement async open if callback is specified
   bool opened = openExternal(url, activate);
-  callback(opened);
+  callback.Run(opened);
   return opened;
 }
 
diff --git a/atom/common/platform_util_win.cc b/atom/common/platform_util_win.cc
index 7eb3c470f7..dd0121b8f7 100644
--- a/atom/common/platform_util_win.cc
+++ b/atom/common/platform_util_win.cc
@@ -323,7 +323,7 @@ bool OpenExternal(const base::string16& url, bool activate) {
 bool OpenExternal(const base::string16& url, bool activate, const OpenExternalCallback& callback) {
   // TODO: Implement async open if callback is specified
   bool opened = openExternal(url, activate);
-  callback(opened);
+  callback.Run(opened);
   return opened;
 }