diff --git a/2018/aoc01/src/main.rs b/2018/aoc01/src/main.rs
index 8f188f2..5af08f6 100644
--- a/2018/aoc01/src/main.rs
+++ b/2018/aoc01/src/main.rs
@@ -14,29 +14,29 @@ fn main() -> Result<()> {
             .expect("Please provide the path to the input file"),
     )?;
 
-    part1(&input);
-    part2(&input);
+    println!("part 1: {}", part1(&input)?);
+    println!("part 2: {}", part2(&input)?);
 
     Ok(())
 }
 
-fn part1(input: &str) {
+fn part1(input: &str) -> Result<i32> {
     let freq = input
         .lines()
         .map(|line| line.parse::<i32>().unwrap())
         .sum::<i32>();
-    println!("{}", freq);
+    Ok(freq)
 }
 
-fn part2(input: &str) {
+fn part2(input: &str) -> Result<i32> {
     let mut freqs = HashSet::new();
     let mut freq = 0;
     loop {
         for line in input.lines() {
-            freq += line.parse::<i32>().unwrap();
+            freq += line.parse::<i32>()?;
             if freqs.contains(&freq) {
                 println!("{}", freq);
-                return;
+                return Ok(freq);
             } else {
                 freqs.insert(freq);
             }
diff --git a/2018/aoc02/src/main.rs b/2018/aoc02/src/main.rs
index 802f59a..2d97726 100644
--- a/2018/aoc02/src/main.rs
+++ b/2018/aoc02/src/main.rs
@@ -14,12 +14,12 @@ fn main() -> Result<()> {
             .expect("Please provide the path to the input file"),
     )?;
 
-    part1(&input)?;
+    println!("part 1: {}", part1(&input)?);
 
     Ok(())
 }
 
-fn part1(input: &str) -> Result<()> {
+fn part1(input: &str) -> Result<u32> {
     let mut twice = 0;
     let mut thrice = 0;
 
@@ -38,7 +38,5 @@ fn part1(input: &str) -> Result<()> {
         }
     }
 
-    println!("{}", twice * thrice);
-
-    Ok(())
+    Ok(twice * thrice)
 }