diff --git a/mozilla/extensions/schema-validation/src/nsSchemaValidator.cpp b/mozilla/extensions/schema-validation/src/nsSchemaValidator.cpp
index f62517ccc1e..83f36c72dc9 100644
--- a/mozilla/extensions/schema-validation/src/nsSchemaValidator.cpp
+++ b/mozilla/extensions/schema-validation/src/nsSchemaValidator.cpp
@@ -3070,7 +3070,8 @@ nsSchemaValidator::IsValidSchemaFloat(const nsAString & aNodeValue,
     }
   }
 
-  *aResult = floatValue;
+  if (aResult)
+    *aResult = floatValue;
   return isValid;
 }