diff --git a/crates/cli/src/repo/branch.rs b/crates/cli/src/repo/branch.rs
index 20fa057..55b8ecd 100644
--- a/crates/cli/src/repo/branch.rs
+++ b/crates/cli/src/repo/branch.rs
@@ -6,7 +6,7 @@ use git_next_core::{
         commit::Message,
         push::{reset, Force},
         repository::open::OpenRepositoryLike,
-        Commit, RepoDetails,
+        Commit, GitRef, RepoDetails,
     },
     RepoConfig,
 };
@@ -18,14 +18,15 @@ use tracing::{info, instrument, warn};
 #[instrument(fields(next), skip_all)]
 pub fn advance_next(
     next: &Commit,
+    main: &Commit,
     dev_commit_history: &[Commit],
     repo_details: RepoDetails,
     repo_config: RepoConfig,
     open_repository: &dyn OpenRepositoryLike,
     message_token: MessageToken,
 ) -> Result<MessageToken> {
-    let commit =
-        find_next_commit_on_dev(next, dev_commit_history).ok_or_else(|| Error::NextAtDev)?;
+    let (commit, force) = find_next_commit_on_dev(next, main, dev_commit_history);
+    let commit = commit.ok_or_else(|| Error::NextAtDev)?;
     validate_commit_message(commit.message())?;
     info!("Advancing next to commit '{}'", commit);
     reset(
@@ -33,7 +34,7 @@ pub fn advance_next(
         &repo_details,
         &repo_config.branches().next(),
         &commit.into(),
-        &Force::No,
+        &force,
     )?;
     Ok(message_token)
 }
@@ -58,15 +59,24 @@ fn validate_commit_message(message: &Message) -> Result<()> {
     }
 }
 
-pub fn find_next_commit_on_dev(next: &Commit, dev_commit_history: &[Commit]) -> Option<Commit> {
+pub fn find_next_commit_on_dev(
+    next: &Commit,
+    main: &Commit,
+    dev_commit_history: &[Commit],
+) -> (Option<Commit>, Force) {
     let mut next_commit: Option<&Commit> = None;
+    let mut force = Force::No;
     for commit in dev_commit_history.iter() {
         if commit == next {
             break;
         };
+        if commit == main {
+            force = Force::From(GitRef::from(next.sha().clone()));
+            break;
+        };
         next_commit.replace(commit);
     }
-    next_commit.cloned()
+    (next_commit.cloned(), force)
 }
 
 // advance main branch to the commit 'next'
diff --git a/crates/cli/src/repo/handlers/advance_next.rs b/crates/cli/src/repo/handlers/advance_next.rs
index c74c917..cdcd2f9 100644
--- a/crates/cli/src/repo/handlers/advance_next.rs
+++ b/crates/cli/src/repo/handlers/advance_next.rs
@@ -6,7 +6,7 @@ use tracing::warn;
 use crate::repo::{
     branch::advance_next,
     do_send,
-    messages::{AdvanceNext, ValidateRepo},
+    messages::{AdvanceNext, AdvanceNextPayload, ValidateRepo},
     RepoActor,
 };
 
@@ -20,13 +20,18 @@ impl Handler<AdvanceNext> for RepoActor {
         let Some(open_repository) = &self.open_repository else {
             return;
         };
-        let (next_commit, dev_commit_history) = msg.unwrap();
+        let AdvanceNextPayload {
+            next,
+            main,
+            dev_commit_history,
+        } = msg.unwrap();
         let repo_details = self.repo_details.clone();
         let repo_config = repo_config.clone();
         let addr = ctx.address();
 
         match advance_next(
-            &next_commit,
+            &next,
+            &main,
             &dev_commit_history,
             repo_details,
             repo_config,
diff --git a/crates/cli/src/repo/handlers/validate_repo.rs b/crates/cli/src/repo/handlers/validate_repo.rs
index 1224fed..0cb18a6 100644
--- a/crates/cli/src/repo/handlers/validate_repo.rs
+++ b/crates/cli/src/repo/handlers/validate_repo.rs
@@ -6,7 +6,7 @@ use tracing::{debug, instrument, Instrument as _};
 
 use crate::repo::{
     do_send, logger,
-    messages::{AdvanceNext, CheckCIStatus, MessageToken, ValidateRepo},
+    messages::{AdvanceNext, AdvanceNextPayload, CheckCIStatus, MessageToken, ValidateRepo},
     notify_user, RepoActor,
 };
 
@@ -60,14 +60,19 @@ impl Handler<ValidateRepo> for RepoActor {
                 next,
                 dev,
                 dev_commit_history,
+                next_is_valid,
             }) => {
                 debug!(%main, %next, %dev, "positions");
-                if next != main {
+                if next_is_valid && next != main {
                     do_send(ctx.address(), CheckCIStatus::new(next), self.log.as_ref());
                 } else if next != dev {
                     do_send(
                         ctx.address(),
-                        AdvanceNext::new((next, dev_commit_history)),
+                        AdvanceNext::new(AdvanceNextPayload {
+                            next,
+                            main,
+                            dev_commit_history,
+                        }),
                         self.log.as_ref(),
                     )
                 } else {
diff --git a/crates/cli/src/repo/messages.rs b/crates/cli/src/repo/messages.rs
index a1c551a..63cb067 100644
--- a/crates/cli/src/repo/messages.rs
+++ b/crates/cli/src/repo/messages.rs
@@ -60,7 +60,14 @@ Contains the commit from the tip of the `next` branch."#); // next commit
 message!(ReceiveCIStatus: (Commit, Status): r#"Notification of the status of the CI checks for the commit.
 
 Contains a tuple of the commit that was checked (the tip of the `next` branch) and the status."#); // commit and it's status
-message!(AdvanceNext: (Commit, Vec<Commit>): "Request to advance the `next` branch on to the next commit on the `dev branch."); // next commit and the dev commit history
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct AdvanceNextPayload {
+    pub next: Commit,
+    pub main: Commit,
+    pub dev_commit_history: Vec<Commit>,
+}
+message!(AdvanceNext: AdvanceNextPayload: "Request to advance the `next` branch on to the next commit on the `dev branch."); // next commit and the dev commit history
 message!(AdvanceMain: Commit: "Request to advance the `main` branch on to same commit as the `next` branch."); // next commit
 message!(WebhookNotification: ForgeNotification: "Notification of a webhook message from the forge.");
 message!(NotifyUser: UserNotification: "Request to send the message payload to the notification webhook");
diff --git a/crates/cli/src/repo/tests/branch/advance_next.rs b/crates/cli/src/repo/tests/branch/advance_next.rs
index 8818fb2..32c443c 100644
--- a/crates/cli/src/repo/tests/branch/advance_next.rs
+++ b/crates/cli/src/repo/tests/branch/advance_next.rs
@@ -7,6 +7,7 @@ mod when_at_dev {
     #[test]
     fn should_not_push() -> TestResult {
         let next = given::a_commit();
+        let main = &next;
         let dev_commit_history = &[next.clone()];
         let fs = given::a_filesystem();
         let repo_config = given::a_repo_config();
@@ -16,6 +17,7 @@ mod when_at_dev {
         let_assert!(
             Err(err) = branch::advance_next(
                 &next,
+                main,
                 dev_commit_history,
                 repo_details,
                 repo_config,
@@ -40,6 +42,7 @@ mod can_advance {
         #[test]
         fn should_not_push() -> TestResult {
             let next = given::a_commit();
+            let main = &next;
             let dev = given::a_commit_with_message("wip: test: message".to_string());
             let dev_commit_history = &[dev, next.clone()];
             let fs = given::a_filesystem();
@@ -50,6 +53,7 @@ mod can_advance {
             let_assert!(
                 Err(err) = branch::advance_next(
                     &next,
+                    main,
                     dev_commit_history,
                     repo_details,
                     repo_config,
@@ -70,6 +74,7 @@ mod can_advance {
         #[test]
         fn should_not_push_and_error() -> TestResult {
             let next = given::a_commit();
+            let main = &next;
             let dev = given::a_commit();
             let dev_commit_history = &[dev, next.clone()];
             let fs = given::a_filesystem();
@@ -80,6 +85,7 @@ mod can_advance {
             let_assert!(
                 Err(err) = branch::advance_next(
                     &next,
+                    main,
                     dev_commit_history,
                     repo_details,
                     repo_config,
@@ -108,6 +114,7 @@ mod can_advance {
             #[test]
             fn should_error() -> TestResult {
                 let next = given::a_commit();
+                let main = &next;
                 let dev = given::a_commit_with_message("test: message".to_string());
                 let dev_commit_history = &[dev, next.clone()];
                 let fs = given::a_filesystem();
@@ -119,6 +126,7 @@ mod can_advance {
                 let_assert!(
                     Err(err) = branch::advance_next(
                         &next,
+                        main,
                         dev_commit_history,
                         repo_details,
                         repo_config,
@@ -139,6 +147,7 @@ mod can_advance {
             #[test]
             fn should_ok() -> TestResult {
                 let next = given::a_commit();
+                let main = &next;
                 let dev = given::a_commit_with_message("test: message".to_string());
                 let dev_commit_history = &[dev, next.clone()];
                 let fs = given::a_filesystem();
@@ -150,6 +159,7 @@ mod can_advance {
                 let_assert!(
                     Ok(mt) = branch::advance_next(
                         &next,
+                        main,
                         dev_commit_history,
                         repo_details,
                         repo_config,
diff --git a/crates/cli/src/repo/tests/branch/mod.rs b/crates/cli/src/repo/tests/branch/mod.rs
index 8634fc4..0341e7d 100644
--- a/crates/cli/src/repo/tests/branch/mod.rs
+++ b/crates/cli/src/repo/tests/branch/mod.rs
@@ -1,3 +1,6 @@
+use git_next_core::git::push::Force;
+use git_next_core::git::GitRef;
+
 //
 use super::*;
 
@@ -8,8 +11,8 @@ use crate::git;
 use crate::repo::branch;
 
 #[actix_rt::test]
-async fn test_find_next_commit_on_dev() {
-    let next = given::a_commit();
+async fn test_find_next_commit_on_dev_when_next_is_at_main() {
+    let next = given::a_commit(); // and main
     let expected = given::a_commit();
     let dev_commit_history = vec![
         given::a_commit(), // dev HEAD
@@ -18,7 +21,30 @@ async fn test_find_next_commit_on_dev() {
         given::a_commit(), // parent of next
     ];
 
-    let next_commit = branch::find_next_commit_on_dev(&next, &dev_commit_history);
+    let (next_commit, force) = branch::find_next_commit_on_dev(&next, &next, &dev_commit_history);
 
     assert_eq!(next_commit, Some(expected), "Found the wrong commit");
+    assert_eq!(force, Force::No, "should not try to force");
+}
+
+#[actix_rt::test]
+async fn test_find_next_commit_on_dev_when_next_is_not_on_dev() {
+    let next = given::a_commit();
+    let main = given::a_commit();
+    let expected = given::a_commit();
+    let dev_commit_history = vec![
+        given::a_commit(), // dev HEAD
+        expected.clone(),
+        main.clone(),      // main - advancing towards dev HEAD
+        given::a_commit(), // parent of next
+    ];
+
+    let (next_commit, force) = branch::find_next_commit_on_dev(&next, &main, &dev_commit_history);
+
+    assert_eq!(next_commit, Some(expected), "Found the wrong commit");
+    assert_eq!(
+        force,
+        Force::From(GitRef::from(next.sha().clone())),
+        "should force back onto dev branch"
+    );
 }
diff --git a/crates/cli/src/repo/tests/handlers/advance_next.rs b/crates/cli/src/repo/tests/handlers/advance_next.rs
index 2f2f741..f068de3 100644
--- a/crates/cli/src/repo/tests/handlers/advance_next.rs
+++ b/crates/cli/src/repo/tests/handlers/advance_next.rs
@@ -1,3 +1,5 @@
+use crate::repo::messages::AdvanceNextPayload;
+
 //
 use super::*;
 
@@ -7,7 +9,7 @@ async fn should_fetch_then_push_then_revalidate() -> TestResult {
     let fs = given::a_filesystem();
     let (mut open_repository, repo_details) = given::an_open_repository(&fs);
     let next_commit = given::a_commit_with_message("feat: next".to_string());
-    let dev_commit_log = vec![
+    let dev_commit_history = vec![
         given::a_commit_with_message("feat: dev".to_string()),
         given::a_commit_with_message("feat: target".to_string()),
         next_commit.clone(),
@@ -31,10 +33,13 @@ async fn should_fetch_then_push_then_revalidate() -> TestResult {
         repo_details,
         given::a_forge(),
     );
-    addr.send(crate::repo::messages::AdvanceNext::new((
-        next_commit.clone(),
-        dev_commit_log,
-    )))
+    addr.send(crate::repo::messages::AdvanceNext::new(
+        AdvanceNextPayload {
+            next: next_commit.clone(),
+            main: next_commit.clone(),
+            dev_commit_history,
+        },
+    ))
     .await?;
     System::current().stop();
 
diff --git a/crates/cli/src/repo/tests/handlers/validate_repo.rs b/crates/cli/src/repo/tests/handlers/validate_repo.rs
index ef25e91..8fce618 100644
--- a/crates/cli/src/repo/tests/handlers/validate_repo.rs
+++ b/crates/cli/src/repo/tests/handlers/validate_repo.rs
@@ -1,8 +1,11 @@
+use crate::repo::messages::{AdvanceNext, AdvanceNextPayload};
+
 //
 use super::*;
 
 #[test_log::test(actix::test)]
-async fn repo_with_next_not_an_ancestor_of_dev_should_be_reset() -> TestResult {
+async fn repo_with_next_not_an_ancestor_of_dev_and_dev_on_main_should_be_reset_to_main(
+) -> TestResult {
     //given
     let fs = given::a_filesystem();
     let (mut open_repository, repo_details) = given::an_open_repository(&fs);
@@ -15,7 +18,7 @@ async fn repo_with_next_not_an_ancestor_of_dev_should_be_reset() -> TestResult {
     // next - based on main
     let next_branch_log = vec![given::a_commit(), main_commit.clone()];
     // dev - based on main, but not on next
-    let dev_branch_log = vec![given::a_commit(), main_commit.clone()];
+    let dev_branch_log = vec![main_commit.clone()];
     // commit_log next - based on main, but not a parent of dev
     open_repository
         .expect_commit_log()
@@ -49,6 +52,62 @@ async fn repo_with_next_not_an_ancestor_of_dev_should_be_reset() -> TestResult {
     Ok(())
 }
 
+#[test_log::test(actix::test)]
+async fn repo_with_next_not_an_ancestor_of_dev_and_dev_ahead_of_main_should_be_reset_to_dev(
+) -> TestResult {
+    //given
+    let fs = given::a_filesystem();
+    let (mut open_repository, repo_details) = given::an_open_repository(&fs);
+    #[allow(clippy::unwrap_used)]
+    let repo_config = repo_details.repo_config.clone().unwrap();
+    expect::fetch_ok(&mut open_repository);
+    let branches = repo_config.branches();
+    // commit_log main
+    let main_commit = expect::main_commit_log(&mut open_repository, branches.main());
+    // next - based on main
+    let next_commit = given::a_commit();
+    let next_branch_log = vec![next_commit.clone(), main_commit.clone()];
+    // dev - based on main, but not on next
+    let dev_branch_log = vec![given::a_commit(), main_commit.clone()];
+    // commit_log next - based on main, but not a parent of dev
+    open_repository
+        .expect_commit_log()
+        .times(1)
+        .with(eq(branches.next()), eq([main_commit.clone()]))
+        .return_once(move |_, _| Ok(next_branch_log));
+    // commit_log dev
+    let dev_branch_log_clone = dev_branch_log.clone();
+    open_repository
+        .expect_commit_log()
+        .times(1)
+        .with(eq(branches.dev()), eq([main_commit.clone()]))
+        .return_once(|_, _| Ok(dev_branch_log_clone));
+    // expect to reset the branch
+    expect::fetch_ok(&mut open_repository);
+    expect::push_ok(&mut open_repository);
+
+    //when
+    let (addr, log) = when::start_actor_with_open_repository(
+        Box::new(open_repository),
+        repo_details,
+        given::a_forge(),
+    );
+    addr.send(crate::repo::messages::ValidateRepo::new(
+        MessageToken::default(),
+    ))
+    .await?;
+    System::current().stop();
+
+    //then
+    let expected = AdvanceNext::new(AdvanceNextPayload {
+        next: next_commit,
+        main: main_commit,
+        dev_commit_history: dev_branch_log,
+    });
+    log.require_message_containing(format!("send: {expected:?}",))?;
+    Ok(())
+}
+
 #[test_log::test(actix::test)]
 async fn repo_with_next_not_on_or_near_main_should_be_reset() -> TestResult {
     //given
@@ -269,7 +328,7 @@ async fn repo_with_dev_ahead_of_next_should_advance_next() -> TestResult {
     open_repository
         .expect_commit_log()
         .times(1)
-        .with(eq(branches.dev()), eq([main_commit]))
+        .with(eq(branches.dev()), eq([main_commit.clone()]))
         .return_once(move |_, _| Ok(dev_commit_log));
 
     //when
@@ -285,9 +344,12 @@ async fn repo_with_dev_ahead_of_next_should_advance_next() -> TestResult {
     System::current().stop();
 
     //then
-    log.require_message_containing(format!(
-        "send: AdvanceNext(({next_commit:?}, {dev_branch_log:?}))"
-    ))?;
+    let expected = AdvanceNext::new(AdvanceNextPayload {
+        next: next_commit,
+        main: main_commit,
+        dev_commit_history: dev_branch_log,
+    });
+    log.require_message_containing(format!("send: {expected:?}"))?;
     Ok(())
 }
 
diff --git a/crates/core/src/git/validation/positions.rs b/crates/core/src/git/validation/positions.rs
index 3ed8b9e..390d5db 100644
--- a/crates/core/src/git/validation/positions.rs
+++ b/crates/core/src/git/validation/positions.rs
@@ -12,6 +12,7 @@ pub struct Positions {
     pub next: git::Commit,
     pub dev: git::Commit,
     pub dev_commit_history: Vec<git::Commit>,
+    pub next_is_valid: bool,
 }
 
 pub fn validate_positions(
@@ -65,16 +66,20 @@ pub fn validate_positions(
         tracing::info!("Main not on same commit as next, or it's parent - resetting next to main",);
         return reset_next_to_main(open_repository, repo_details, &main, &next, &next_branch);
     }
-    // verify that next is an ancestor of dev, else reset it back to main
-    if is_not_based_on(&commit_histories.dev, &next) {
+    // verify that next is an ancestor of dev, else reset it back to main if dev not ahead of main
+    if is_not_based_on(&commit_histories.dev, &next)
+        && commit_histories.main.first() == commit_histories.dev.first()
+    {
         tracing::info!("Next is not an ancestor of dev - resetting next to main");
         return reset_next_to_main(open_repository, repo_details, &main, &next, &next_branch);
     }
+    let next_is_valid = is_based_on(&commit_histories.dev, &next);
     Ok(git::validation::positions::Positions {
         main,
         next,
         dev,
         dev_commit_history: commit_histories.dev,
+        next_is_valid,
     })
 }
 
@@ -103,7 +108,11 @@ fn reset_next_to_main(
 }
 
 fn is_not_based_on(commits: &[git::commit::Commit], needle: &git::Commit) -> bool {
-    commits.iter().filter(|commit| *commit == needle).count() == 0
+    !is_based_on(commits, needle)
+}
+
+fn is_based_on(commits: &[git::commit::Commit], needle: &git::Commit) -> bool {
+    commits.iter().any(|commit| commit == needle)
 }
 
 fn get_commit_histories(
diff --git a/crates/core/src/git/validation/tests.rs b/crates/core/src/git/validation/tests.rs
index 902324c..92d024f 100644
--- a/crates/core/src/git/validation/tests.rs
+++ b/crates/core/src/git/validation/tests.rs
@@ -410,9 +410,10 @@ mod positions {
                 git::validation::positions::Error::NonRetryable(_)
             ));
         }
-
         #[test]
-        fn where_dev_branch_is_not_based_on_next_should_reset_next_branch_to_main_and_then_error() {
+        #[allow(clippy::expect_used)]
+        fn where_dev_branch_is_on_main_and_next_is_not_should_reset_next_branch_to_main_and_retryable_error(
+        ) {
             //given
             let_assert!(Ok(fs) = kxio::fs::temp(), "temp fs");
             let gitdir = GitDir::new(fs.base().to_path_buf(), StoragePathType::Internal);
@@ -424,12 +425,11 @@ mod positions {
                 fs.clone(),
                 |branches, gitdir, fs| {
                     //        /--- 3 next
-                    // 0 --- 1  main
-                    //        \--- 2 dev
+                    // 0 --- 1  main & dev
                     // add a commit to main (0 -> 1)
                     then::create_a_commit_on_branch(fs, gitdir, &branches.main())?;
-                    // add a commit to dev (1 -> 2)
-                    then::create_a_commit_on_branch(fs, gitdir, &branches.dev())?;
+                    // create dev branch on main (1)
+                    then::git_switch(&branches.dev(), gitdir)?;
                     // switch back to main (1)
                     then::git_switch(&branches.main(), gitdir)?;
                     // add a commit to next (1 -> 3)
@@ -496,7 +496,9 @@ mod positions {
         }
 
         #[test]
-        fn where_dev_branch_is_not_based_on_next_and_reset_of_next_fails_should_error() {
+        #[allow(clippy::expect_used)]
+        fn where_dev_branch_is_not_based_on_next_should_reset_next_branch_to_next_commit_on_dev_and_retryable_error(
+        ) {
             //given
             let_assert!(Ok(fs) = kxio::fs::temp(), "temp fs");
             let gitdir = GitDir::new(fs.base().to_path_buf(), StoragePathType::Internal);
@@ -537,8 +539,25 @@ mod positions {
                 repo_config.branches().clone(),
                 gitdir.clone(),
                 fs.clone(),
-                |_repo_details, _branch_name, _gitref, _force, _repo_branches, _gitdir, _fs| {
-                    git::push::Result::Err(git::push::Error::Lock)
+                |_repo_details, branch_name, gitref, force, repo_branches, gitdir, fs| {
+                    assert_eq!(
+                        branch_name,
+                        &repo_branches.next(),
+                        "branch to reset should be 'next'"
+                    );
+                    let sha_dev = then::get_sha_for_branch(fs, gitdir, &repo_branches.dev())?;
+                    assert_eq!(
+                        gitref,
+                        &git::GitRef::from(sha_dev),
+                        "should reset to the sha of the next commit on 'dev' branch"
+                    );
+                    let sha_next = then::get_sha_for_branch(fs, gitdir, &repo_branches.next())?;
+                    assert_eq!(
+                        force,
+                        &git::push::Force::From(sha_next.into()),
+                        "should force push only if next is on expected sha"
+                    );
+                    git::push::Result::Ok(())
                 },
             ));
             let_assert!(
@@ -549,21 +568,30 @@ mod positions {
 
             //when
             let_assert!(
-                Err(err) =
+                Ok(positions) =
                     validate_positions(&*open_repository, &repo_details, repo_config.clone()),
                 "validate"
             );
 
             //then
-            println!("Got: {err:?}");
+            println!("positions: {positions:#?}");
+
             let_assert!(
-                Ok(_) = then::get_sha_for_branch(&fs, &gitdir, &repo_config.branches().next()),
-                "load next branch sha"
+                Ok(main_sha) =
+                    then::get_sha_for_branch(&fs, &gitdir, &repo_config.branches().main())
             );
-            assert!(matches!(
-                err,
-                git::validation::positions::Error::NonRetryable(_)
-            ));
+            assert_eq!(positions.main.sha(), &main_sha);
+
+            let_assert!(
+                Ok(next_sha) =
+                    then::get_sha_for_branch(&fs, &gitdir, &repo_config.branches().next())
+            );
+            assert_eq!(positions.next.sha(), &next_sha);
+
+            let_assert!(
+                Ok(dev_sha) = then::get_sha_for_branch(&fs, &gitdir, &repo_config.branches().dev())
+            );
+            assert_eq!(positions.dev.sha(), &dev_sha);
         }
 
         #[test]