--- a/gfx/thebes/gfxDWriteFontList.cpp
+++ b/gfx/thebes/gfxDWriteFontList.cpp
@@ -1516,17 +1516,19 @@ private:
 
 void
 DirectWriteFontInfo::LoadFontFamilyData(const nsAString& aFamilyName)
 {
     // lookup the family
     nsAutoTArray<wchar_t, 32> famName;
 
     uint32_t len = aFamilyName.Length();
-    famName.SetLength(len + 1, fallible);
+    if(!famName.SetLength(len + 1, fallible)) {
+        return;
+    }
     memcpy(famName.Elements(), aFamilyName.BeginReading(), len * sizeof(char16_t));
     famName[len] = 0;
 
     HRESULT hr;
     BOOL exists = false;
 
     uint32_t index;
     nsRefPtr<IDWriteFontFamily> family;