diff --git a/2022/Cargo.toml b/2022/Cargo.toml
index 82f2248..ea67c1c 100644
--- a/2022/Cargo.toml
+++ b/2022/Cargo.toml
@@ -9,4 +9,3 @@ edition = "2021"
 anyhow = "1.0"
 regex = "1"
 lazy_static = "1.4.0"
-itertools = "0.10.5"
diff --git a/2022/src/bin/day6.rs b/2022/src/bin/day6.rs
index 19e288a..b460eec 100644
--- a/2022/src/bin/day6.rs
+++ b/2022/src/bin/day6.rs
@@ -1,7 +1,6 @@
 #![feature(test)]
 use anyhow::Result;
 use aoc::Solver;
-use itertools::Itertools;
 
 // -- Runners --
 fn main() -> Result<()> {
@@ -70,7 +69,15 @@ mod tests {
 
 // -- Helpers --
 fn is_start_marker(window: &[char]) -> bool {
-    window.len() == window.iter().unique().count()
+    for i in 0..window.len() {
+        for j in i+1..window.len() {
+            if window[i] == window[j] {
+                return false;
+            }
+        }
+    }
+
+    return true;
 }
 
 fn solution(input: &str, length: usize) -> usize {