diff --git a/compiler/gen_dev/src/lib.rs b/compiler/gen_dev/src/lib.rs
index df76cd03f3..0bc6a20315 100644
--- a/compiler/gen_dev/src/lib.rs
+++ b/compiler/gen_dev/src/lib.rs
@@ -741,6 +741,8 @@ trait Backend<'a> {
     /// scan_ast runs through the ast and fill the last seen map.
     /// This must iterate through the ast in the same way that build_stmt does. i.e. then before else.
     fn scan_ast(&mut self, stmt: &Stmt<'a>) {
+        // Join map keeps track of join point paramaters so that we can keep them around while they still might be jumped to.
+        let mut join_map: MutMap<JoinPointId, &'a [Param<'a>]> = MutMap::default();
         match stmt {
             Stmt::Let(sym, expr, _, following) => {
                 self.set_last_seen(*sym, stmt);
@@ -829,8 +831,10 @@ trait Backend<'a> {
                 parameters,
                 body: continuation,
                 remainder,
+                id,
                 ..
             } => {
+                join_map.insert(*id, parameters);
                 for param in *parameters {
                     self.set_last_seen(param.symbol, stmt);
                 }
@@ -838,6 +842,12 @@ trait Backend<'a> {
                 self.scan_ast(remainder);
             }
             Stmt::Jump(JoinPointId(sym), symbols) => {
+                if let Some(parameters) = join_map.get(&JoinPointId(*sym)) {
+                    // Keep the parameters around. They will be overwritten when jumping.
+                    for param in *parameters {
+                        self.set_last_seen(param.symbol, stmt);
+                    }
+                }
                 self.set_last_seen(*sym, stmt);
                 for sym in *symbols {
                     self.set_last_seen(*sym, stmt);