diff --git a/src/default-handlers.md b/src/default-handlers.md
index baa2bc8e..3833b110 100644
--- a/src/default-handlers.md
+++ b/src/default-handlers.md
@@ -8,6 +8,7 @@ providing a handler in a `run-with` block.
 For example, we can write:
 
 ```flix
+use Sys.Env
 use Time.Clock
 
 def main(): Unit \ {Clock, Env, Logger} =
@@ -21,6 +22,7 @@ def main(): Unit \ {Clock, Env, Logger} =
 which the Flix compiler translates to:
 
 ```flix
+use Sys.Env
 use Time.Clock
 
 def main(): Unit \ IO =
@@ -41,6 +43,8 @@ respective effects.
 For example, `Clock.runWithIO` is declared as:
 
 ```flix
+use Time.Clock
+
 @DefaultHandler
 pub def runWithIO(f: Unit -> a \ ef): a \ (ef - Clock) + IO = ...
 ```
diff --git a/src/main.md b/src/main.md
index 02ea3843..9ab745f5 100644
--- a/src/main.md
+++ b/src/main.md
@@ -22,6 +22,9 @@ compiler. See [Default Handlers](./default-handlers.md) for details.
 For example, main can use the `Env` and `Exit` effects:
 
 ```flix
+use Sys.Env
+use Sys.Exit
+
 def main(): Unit \ {Env, Exit} =
     let args = Env.getArgs();
     match List.head(args) {
@@ -39,6 +42,8 @@ The command line arguments passed to the program can be accessed by calling
 `Env.getArgs()` through the `Env` effect:
 
 ```flix
+use Sys.Env
+
 def main(): Unit \ {Env, IO} =
     let args = Env.getArgs();
     println("Arguments: ${args}")
@@ -49,6 +54,8 @@ def main(): Unit \ {Env, IO} =
 The program can be terminated with a specific exit code using `Exit.exit`:
 
 ```flix
+use Sys.Exit
+
 def main(): Unit \ Exit =
     Exit.exit(0)
 ```