diff --git a/atom/browser/api/atom_api_window.cc b/atom/browser/api/atom_api_window.cc
index 760a94a0ef4d..02961f95f669 100644
--- a/atom/browser/api/atom_api_window.cc
+++ b/atom/browser/api/atom_api_window.cc
@@ -148,7 +148,7 @@ void Window::Unmaximize() {
   window_->Unmaximize();
 }
 
-void Window::IsMaximized() {
+bool Window::IsMaximized() {
   return window_->IsMaximized();
 }
 
diff --git a/atom/browser/native_window_mac.mm b/atom/browser/native_window_mac.mm
index ff51400b3a52..154319845f13 100644
--- a/atom/browser/native_window_mac.mm
+++ b/atom/browser/native_window_mac.mm
@@ -279,7 +279,7 @@ void NativeWindowMac::Unmaximize() {
   [window_ zoom:nil];
 }
 
-void NativeWindowMac::IsMaximized() {
+bool NativeWindowMac::IsMaximized() {
   return [window_ isZoomed];
 }