diff --git a/Source/Urho3D/Container/Str.h b/Source/Urho3D/Container/Str.h
index ff2944892..576700341 100644
--- a/Source/Urho3D/Container/Str.h
+++ b/Source/Urho3D/Container/Str.h
@@ -165,7 +165,7 @@ class URHO3D_API String
     /// Destruct.
     ~String()
     {
-        if (capacity_)
+        if (capacity_ && buffer_ != &endZero)
             delete[] buffer_;
     }