diff --git a/src/main.rs b/src/main.rs
index 76bfae3..1b654f3 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,4 +1,7 @@
-use std::fs;
+use std::{
+    fs::{self, File},
+    io::{self, BufRead},
+};
 
 use clap::{Args, Parser, Subcommand};
 use color_eyre::eyre::Result;
@@ -16,6 +19,17 @@ struct Cli {
 enum CliCommands {
     Track(Track),
     GetDiff(GetDiff),
+    UpdatePrs(UpdatePRs),
+}
+
+#[derive(Args, Debug, Default)]
+struct UpdatePRs {
+    #[arg(long, default_value_t = ("./pr.txt".to_string()))]
+    pr_file: String,
+    #[arg(long, default_value_t = ("./patches/PR".to_string()))]
+    path: String,
+    #[arg(long, default_value_t = ("nixos-unstable".to_string()))]
+    branch: String,
 }
 
 #[derive(Args, Debug, Default)]
@@ -41,9 +55,10 @@ const BRANCHES: &[&str] = &[
 struct PR {
     title: String,
     state: String,
-    merged: bool,
+    merged: Option<bool>,
     merged_at: Option<String>,
-    merge_commit_sha: String,
+    // merge conflicts don't have a merge_commit_sha
+    merge_commit_sha: Option<String>,
     mergeable: bool,
 }
 
@@ -64,16 +79,18 @@ async fn get_pr(pr: &str, client: &Client) -> Result<PR> {
     Ok(v)
 }
 async fn contains(branch: &str, pr: &PR, client: &Client) -> Result<bool> {
-    let req = client
-        .get(format!(
-            "https://api.github.com/repos/nixos/nixpkgs/compare/{}...{}",
-            branch, pr.merge_commit_sha
-        ))
-        .send();
-    let text = &req.await?.text().await?;
-    let v: Compare = serde_json::from_str(text)?;
-    if v.status == "identical" || v.status == "behind" {
-        return Ok(true);
+    if let Some(sha) = &pr.merge_commit_sha {
+        let req = client
+            .get(format!(
+                "https://api.github.com/repos/nixos/nixpkgs/compare/{}...{}",
+                branch, sha
+            ))
+            .send();
+        let text = &req.await?.text().await?;
+        let v: Compare = serde_json::from_str(text)?;
+        if v.status == "identical" || v.status == "behind" {
+            return Ok(true);
+        }
     }
     Ok(false)
 }
@@ -101,6 +118,25 @@ async fn main() -> Result<()> {
         CliCommands::GetDiff(opts) => {
             get_diff(&opts.pr, &opts.path, &client).await?;
         }
+        CliCommands::UpdatePrs(opts) => {
+            let mut trackable: Vec<String> = Vec::new();
+            {
+                let file = File::open(opts.pr_file.clone())?;
+                for l in io::BufReader::new(file).lines() {
+                    let l = l?;
+                    let pr = get_pr(&l, &client).await?;
+                    println!("Fetching diff for PR #{}: {}", l, pr.title);
+                    if contains(&opts.branch, &pr, &client).await? {
+                        println!("PR has reached {}, removing diff", opts.branch);
+                        fs::remove_file(format!("{}/{}.diff", opts.path, l))?;
+                    } else {
+                        get_diff(&l, &opts.path, &client).await?;
+                        trackable.push(l.clone());
+                    }
+                }
+            }
+            fs::write(&opts.pr_file, trackable.join("\n"))?;
+        }
     };
     Ok(())
 }