diff --git a/src/main.rs b/src/main.rs
index f357562..1c67f06 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -23,24 +23,26 @@ fn main() -> Result<()> {
         content.as_str(),
         args.pattern.as_str(),
         &mut std::io::stdout(),
-    );
+    )?;
 
     Ok(())
 }
 
-fn find_matches(content: &str, pattern: &str, mut writer: impl std::io::Write) {
+fn find_matches(content: &str, pattern: &str, mut writer: impl std::io::Write) -> Result<()> {
     for line in content.lines() {
         if line.contains(pattern) {
-            writeln!(writer, "{}", line);
+            writeln!(writer, "{}", line)?;
         }
     }
+    Ok(())
 }
 
 #[test]
-fn find_a_match() {
+fn find_a_match() -> Result<(), Box<dyn std::error::Error>> {
     let mut result = Vec::new();
-    find_matches("lorem ipsum\ndolar sit amet", "lorem", &mut result);
-    assert_eq!(result, b"lorem ipsum\n")
+    find_matches("lorem ipsum\ndolar sit amet", "lorem", &mut result)?;
+    assert_eq!(result, b"lorem ipsum\n");
+    Ok(())
 }
 
 #[allow(dead_code)]