--- a/netwerk/base/nsSimpleURI.cpp
+++ b/netwerk/base/nsSimpleURI.cpp
@@ -419,17 +419,20 @@ nsSimpleURI::GetPath(nsACString &result)
     return NS_OK;
 }
 
 NS_IMETHODIMP
 nsSimpleURI::SetPath(const nsACString &aPath)
 {
     NS_ENSURE_STATE(mMutable);
 
-    nsAutoCString path(aPath);
+    nsAutoCString path;
+    if (!path.Assign(aPath, fallible)) {
+        return NS_ERROR_OUT_OF_MEMORY;
+    }
     int32_t queryPos = path.FindChar('?');
     int32_t hashPos = path.FindChar('#');
 
     if (queryPos != kNotFound && hashPos != kNotFound && hashPos < queryPos) {
         queryPos = kNotFound;
     }
 
     nsAutoCString query;