diff --git a/Cargo.lock b/Cargo.lock
index 9526d3f..c7a74d2 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -17,6 +17,7 @@ dependencies = [
 name = "aoc2015"
 version = "0.1.0"
 dependencies = [
+ "anyhow",
  "aoc",
  "criterion",
  "md-5",
diff --git a/aoc2015/Cargo.toml b/aoc2015/Cargo.toml
index 2144355..1c46488 100644
--- a/aoc2015/Cargo.toml
+++ b/aoc2015/Cargo.toml
@@ -13,6 +13,7 @@ criterion = "0.3"
 [dependencies]
 
 aoc = { path = "../aoc" }
+anyhow = "1.0"
 md-5 = "0.8"
 
 [lib]
diff --git a/aoc2015/src/day01.rs b/aoc2015/src/day01.rs
index e722345..2ee1bbd 100644
--- a/aoc2015/src/day01.rs
+++ b/aoc2015/src/day01.rs
@@ -1,7 +1,6 @@
 use std::fmt::Write;
 
-use aoc::err;
-use aoc::Result;
+use anyhow::{anyhow, bail, Result};
 
 const INPUT: &str = include_str!("../input/day01.txt");
 
@@ -33,7 +32,7 @@ fn part2(input: &str) -> Result<usize> {
         match c {
             '(' => sum += 1,
             ')' => sum -= 1,
-            _ => return Err(err!("unidentified character in input: {}", c)),
+            _ => bail!("unidentified character in input: {}", c),
         };
 
         if sum < 0 {
@@ -43,7 +42,7 @@ fn part2(input: &str) -> Result<usize> {
     }
 
     match res {
-        0 => Err(err!("never reached the basement...")),
+        0 => Err(anyhow!("never reached the basement...")),
         _ => Ok(res),
     }
 }
diff --git a/aoc2015/src/day02.rs b/aoc2015/src/day02.rs
index ba6818d..bb5a7d6 100644
--- a/aoc2015/src/day02.rs
+++ b/aoc2015/src/day02.rs
@@ -1,9 +1,7 @@
-use std::error::Error;
 use std::fmt::Write;
 use std::str::FromStr;
 
-use aoc::err;
-use aoc::Result;
+use anyhow::{Context, Result};
 
 const INPUT: &str = include_str!("../input/day02.txt");
 
@@ -64,19 +62,19 @@ struct Present {
 }
 
 impl FromStr for Present {
-    type Err = Box<dyn Error>;
+    type Err = anyhow::Error;
 
     fn from_str(s: &str) -> Result<Self> {
         let x = s
             .find('x')
-            .ok_or_else(|| err!("couldn't find first `x` in {}", s))?;
+            .with_context(|| format!("couldn't find first `x` in {}", s))?;
 
         let length = s[..x].parse()?;
 
         let s = &s[(x + 1)..];
         let x = s
             .find('x')
-            .ok_or_else(|| err!("couldn't find second `x` in {}", s))?;
+            .with_context(|| format!("couldn't find second `x` in {}", s))?;
 
         let width = s[..x].parse()?;
 
diff --git a/aoc2015/src/day03.rs b/aoc2015/src/day03.rs
index b91c8ed..3c25b69 100644
--- a/aoc2015/src/day03.rs
+++ b/aoc2015/src/day03.rs
@@ -1,8 +1,7 @@
 use std::collections::HashSet;
 use std::fmt::Write;
 
-use aoc::err;
-use aoc::Result;
+use anyhow::{bail, Result};
 
 const INPUT: &str = include_str!("../input/day03.txt");
 
@@ -29,7 +28,7 @@ fn part1(input: &str) -> Result<usize> {
             '<' => x -= 1,
             '^' => y -= 1,
             'v' => y += 1,
-            _ => return Err(err!("unidentified move: `{}`", c)),
+            _ => bail!("unidentified move: `{}`", c),
         }
 
         houses.insert((x, y));
@@ -56,7 +55,7 @@ fn part2(input: &str) -> Result<usize> {
                 '<' => santa_x -= 1,
                 '^' => santa_y -= 1,
                 'v' => santa_y += 1,
-                _ => return Err(err!("unidentified move: `{}`", c)),
+                _ => bail!("unidentified move: `{}`", c),
             }
 
             houses.insert((santa_x, santa_y));
@@ -66,7 +65,7 @@ fn part2(input: &str) -> Result<usize> {
                 '<' => robot_x -= 1,
                 '^' => robot_y -= 1,
                 'v' => robot_y += 1,
-                _ => return Err(err!("unidentified move: `{}`", c)),
+                _ => bail!("unidentified move: `{}`", c),
             }
 
             houses.insert((robot_x, robot_y));
diff --git a/aoc2015/src/day04.rs b/aoc2015/src/day04.rs
index b59e0fe..beeb0e8 100644
--- a/aoc2015/src/day04.rs
+++ b/aoc2015/src/day04.rs
@@ -2,8 +2,7 @@ use std::fmt::Write;
 
 use md5::{Digest, Md5};
 
-use aoc::err;
-use aoc::Result;
+use anyhow::{anyhow, Result};
 
 const INPUT: &str = include_str!("../input/day04.txt");
 
@@ -33,7 +32,7 @@ fn part1(input: &str) -> Result<u64> {
         }
     }
 
-    Err(err!("couldn't find a suitable number"))
+    Err(anyhow!("couldn't find a suitable number"))
 }
 
 fn part2(input: &str) -> Result<u64> {
@@ -53,7 +52,7 @@ fn part2(input: &str) -> Result<u64> {
         }
     }
 
-    Err(err!("couldn't find a suitable number"))
+    Err(anyhow!("couldn't find a suitable number"))
 }
 
 #[cfg(test)]
diff --git a/aoc2015/src/day05.rs b/aoc2015/src/day05.rs
index 41c15cd..e696295 100644
--- a/aoc2015/src/day05.rs
+++ b/aoc2015/src/day05.rs
@@ -1,6 +1,6 @@
 use std::fmt::Write;
 
-use aoc::Result;
+use anyhow::Result;
 
 const INPUT: &str = include_str!("../input/day05.txt");
 
diff --git a/aoc2015/src/day06.rs b/aoc2015/src/day06.rs
index 245aa1f..3213d07 100644
--- a/aoc2015/src/day06.rs
+++ b/aoc2015/src/day06.rs
@@ -1,9 +1,7 @@
-use std::error::Error;
 use std::fmt::Write;
 use std::str::FromStr;
 
-use aoc::err;
-use aoc::Result;
+use anyhow::{bail, Context, Result};
 
 const INPUT: &str = include_str!("../input/day06.txt");
 
@@ -22,7 +20,7 @@ fn part1(input: &str) -> Result<usize> {
         .map(|line| {
             line.trim_end()
                 .parse()
-                .map_err(|e| err!("couldn't parse instruction: {}", e))
+                .context("couldn't parse instruction: {}")
         })
         .collect::<Result<Vec<Instruction>>>()?;
 
@@ -61,7 +59,7 @@ fn part2(input: &str) -> Result<u64> {
         .map(|line| {
             line.trim_end()
                 .parse()
-                .map_err(|e| err!("couldn't parse instruction: {}", e))
+                .context("couldn't parse instruction: {}")
         })
         .collect::<Result<Vec<Instruction>>>()?;
 
@@ -119,19 +117,19 @@ impl IntoIterator for Instruction {
 }
 
 impl FromStr for Instruction {
-    type Err = Box<dyn Error>;
+    type Err = anyhow::Error;
 
     fn from_str(s: &str) -> Result<Self> {
         let mut space = s
             .find(' ')
-            .ok_or_else(|| err!("couldn't parse instruction: {}", s))?;
+            .with_context(|| format!("couldn't parse instruction: {}", s))?;
 
         let action = if &s[..space] == "toggle" {
             Action::Toggle
         } else if &s[..space] == "turn" {
             space = s[(space + 1)..]
                 .find(' ')
-                .ok_or_else(|| err!("couldn't parse instruction: {}", s))?
+                .with_context(|| format!("couldn't parse instruction: {}", s))?
                 + space
                 + 1;
             if &s[..space] == "turn on" {
@@ -139,22 +137,22 @@ impl FromStr for Instruction {
             } else if &s[..space] == "turn off" {
                 Action::TurnOff
             } else {
-                return Err(err!("couldn't identify action: {}", &s[..space]));
+                bail!("couldn't identify action: {}", &s[..space]);
             }
         } else {
-            return Err(err!("couldn't identify action: {}", s));
+            bail!("couldn't identify action: {}", s);
         };
         let s = &s[(space + 1)..];
 
         let comma = s
             .find(',')
-            .ok_or_else(|| err!("couldn't parse instruction: {}", s))?;
+            .with_context(|| format!("couldn't parse instruction: {}", s))?;
         let x = s[..comma].parse()?;
         let s = &s[(comma + 1)..];
 
         let space = s
             .find(' ')
-            .ok_or_else(|| err!("couldn't parse instruction: {}", s))?;
+            .with_context(|| format!("couldn't parse instruction: {}", s))?;
         let y = s[..space].parse()?;
         let s = &s[(space + 1)..];
 
@@ -162,12 +160,12 @@ impl FromStr for Instruction {
 
         let through = s
             .find("through ")
-            .ok_or_else(|| err!("couldn't parse instruction: {}", s))?;
+            .with_context(|| format!("couldn't parse instruction: {}", s))?;
         let s = &s[(through + 8)..];
 
         let comma = s
             .find(',')
-            .ok_or_else(|| err!("couldn't parse instruction: {}", s))?;
+            .with_context(|| format!("couldn't parse instruction: {}", s))?;
         let x = s[..comma].parse()?;
         let s = &s[(comma + 1)..];
 
diff --git a/aoc2015/src/main.rs b/aoc2015/src/main.rs
index d712f92..6dfde82 100644
--- a/aoc2015/src/main.rs
+++ b/aoc2015/src/main.rs
@@ -1,5 +1,6 @@
+use anyhow::Result;
+
 use aoc::DayFunc;
-use aoc::Result;
 
 use aoc2015::day01;
 use aoc2015::day02;