diff --git a/crates/common/src/config.rs b/crates/common/src/config.rs
index 66f65f1..4de4587 100644
--- a/crates/common/src/config.rs
+++ b/crates/common/src/config.rs
@@ -923,3 +923,20 @@ unsupported_timeout = "2h 30m"
     );
   }
 }
+
+#[cfg(test)]
+mod humantime_option_test {
+    use super::*;
+    
+    #[test]
+    fn test_option_humantime_missing() {
+        let toml = r#"
+workers = 4
+poll_interval = 5
+build_timeout = 3600
+work_dir = "/tmp/fc"
+        "#;
+        let config: QueueRunnerConfig = toml::from_str(toml).unwrap();
+        assert_eq!(config.unsupported_timeout, None);
+    }
+}
diff --git a/crates/queue-runner/src/main.rs b/crates/queue-runner/src/main.rs
index f109d55..f1ab427 100644
--- a/crates/queue-runner/src/main.rs
+++ b/crates/queue-runner/src/main.rs
@@ -40,6 +40,7 @@ async fn main() -> anyhow::Result<()> {
   let failed_paths_cache = qr_config.failed_paths_cache;
   let failed_paths_ttl = qr_config.failed_paths_ttl;
   let work_dir = qr_config.work_dir;
+  let unsupported_timeout = qr_config.unsupported_timeout;
 
   // Ensure the work directory exists
   tokio::fs::create_dir_all(&work_dir).await?;
@@ -82,7 +83,7 @@ async fn main() -> anyhow::Result<()> {
   let active_builds = worker_pool.active_builds().clone();
 
   tokio::select! {
-      result = fc_queue_runner::runner_loop::run(db.pool().clone(), worker_pool, poll_interval, wakeup, strict_errors, failed_paths_cache, notifications_config.clone()) => {
+      result = fc_queue_runner::runner_loop::run(db.pool().clone(), worker_pool, poll_interval, wakeup, strict_errors, failed_paths_cache, notifications_config.clone(), unsupported_timeout) => {
           if let Err(e) = result {
               tracing::error!("Runner loop failed: {e}");
           }
diff --git a/crates/queue-runner/src/runner_loop.rs b/crates/queue-runner/src/runner_loop.rs
index 451f032..4f3f24f 100644
--- a/crates/queue-runner/src/runner_loop.rs
+++ b/crates/queue-runner/src/runner_loop.rs
@@ -38,6 +38,7 @@ pub async fn run(
   strict_errors: bool,
   failed_paths_cache: bool,
   notifications_config: fc_common::config::NotificationsConfig,
+  unsupported_timeout: Option<Duration>,
 ) -> anyhow::Result<()> {
   // Reset orphaned builds from previous crashes (older than 5 minutes)
   match repo::builds::reset_orphaned(&pool, 300).await {
@@ -207,6 +208,52 @@ pub async fn run(
             },
           }
 
+          // Unsupported system timeout: abort builds with no available builders
+          if let Some(timeout) = unsupported_timeout {
+            if let Some(system) = &build.system {
+              match repo::remote_builders::find_for_system(&pool, system).await {
+                Ok(builders) if builders.is_empty() => {
+                  let timeout_at = build.created_at + timeout;
+                  if chrono::Utc::now() > timeout_at {
+                    tracing::info!(
+                      build_id = %build.id,
+                      system = %system,
+                      timeout = ?timeout,
+                      "Aborting build: no builder available for system type"
+                    );
+
+                    if let Err(e) = repo::builds::start(&pool, build.id).await {
+                      tracing::warn!(build_id = %build.id, "Failed to start unsupported build: {e}");
+                    }
+
+                    if let Err(e) = repo::builds::complete(
+                      &pool,
+                      build.id,
+                      BuildStatus::UnsupportedSystem,
+                      None,
+                      None,
+                      Some("No builder available for system type"),
+                    )
+                    .await
+                    {
+                      tracing::warn!(build_id = %build.id, "Failed to complete unsupported build: {e}");
+                    }
+
+                    continue;
+                  }
+                },
+                Ok(_) => {}, // Builders available, proceed normally
+                Err(e) => {
+                  tracing::error!(
+                    build_id = %build.id,
+                    "Failed to check builders for unsupported system: {e}"
+                  );
+                  continue;
+                },
+              }
+            }
+          }
+
           // One-at-a-time scheduling: check if jobset allows concurrent builds
           // First, get the evaluation to find the jobset
           let eval =