diff --git a/React/CoreModules/RCTDeviceInfo.mm b/React/CoreModules/RCTDeviceInfo.mm
index e3ac4339915..1f0bd576a4b 100644
--- a/React/CoreModules/RCTDeviceInfo.mm
+++ b/React/CoreModules/RCTDeviceInfo.mm
@@ -93,7 +93,8 @@ static BOOL RCTIsIPhoneX()
 static NSDictionary *RCTExportedDimensions(RCTBridge *bridge)
 {
   RCTAssertMainQueue();
-  RCTDimensions dimensions = RCTGetDimensions(bridge.accessibilityManager.multiplier);
+  RCTAssert(bridge, @"Bridge must not be `nil`.");
+  RCTDimensions dimensions = RCTGetDimensions(bridge.accessibilityManager.multiplier ?: 1.0);
   __typeof(dimensions.window) window = dimensions.window;
   NSDictionary<NSString *, NSNumber *> *dimsWindow = @{
     @"width" : @(window.width),
diff --git a/React/UIUtils/RCTUIUtils.m b/React/UIUtils/RCTUIUtils.m
index 2d3243c5783..ba9443e298a 100644
--- a/React/UIUtils/RCTUIUtils.m
+++ b/React/UIUtils/RCTUIUtils.m
@@ -16,7 +16,8 @@ RCTDimensions RCTGetDimensions(CGFloat fontScale)
 
   UIView *mainWindow;
   mainWindow = RCTKeyWindow();
-  CGSize windowSize = mainWindow.bounds.size;
+  // We fallback to screen size if a key window is not found.
+  CGSize windowSize = mainWindow ? mainWindow.bounds.size : screenSize;
 
   RCTDimensions result;
   typeof(result.screen) dimsScreen = {