diff --git a/src/Config/ConfigExtensions.cs b/src/Config/ConfigExtensions.cs
index 595fa67..e11b9ee 100644
--- a/src/Config/ConfigExtensions.cs
+++ b/src/Config/ConfigExtensions.cs
@@ -961,7 +961,7 @@ static Config Write(Config config, ConfigLevel level, Func<Config, Config> funct
                 return function(cfg);
             }
 
-            throw new ArgumentException($"Could write variable for level {level} using the given config.", nameof(config));
+            throw new ArgumentException($"Could not write variable for level {level} using the given config.", nameof(config));
         }
     }
 }