diff --git a/src/java.base/share/classes/java/util/concurrent/StructuredTaskScope.java b/src/java.base/share/classes/java/util/concurrent/StructuredTaskScope.java
index 5440f2e747f..f4e624c5852 100644
--- a/src/java.base/share/classes/java/util/concurrent/StructuredTaskScope.java
+++ b/src/java.base/share/classes/java/util/concurrent/StructuredTaskScope.java
@@ -576,8 +576,6 @@ public class StructuredTaskScope<T> implements AutoCloseable {
         }
 
         SubtaskImpl<U> subtask = new SubtaskImpl<>(this, task, round);
-        boolean started = false;
-
         if (s < SHUTDOWN) {
             // create thread to run task
             Thread thread = factory.newThread(subtask);
@@ -588,15 +586,14 @@ public class StructuredTaskScope<T> implements AutoCloseable {
             // attempt to start the thread
             try {
                 flock.start(thread);
-                started = true;
             } catch (IllegalStateException e) {
                 // shutdown by another thread, or underlying flock is shutdown due
                 // to unstructured use
             }
         }
 
-        // force owner to join if thread started
-        if (started && Thread.currentThread() == flock.owner() && round > forkRound) {
+        // force owner to join if this is the first fork in the round
+        if (Thread.currentThread() == flock.owner() && round > forkRound) {
             forkRound = round;
         }
 
@@ -939,7 +936,8 @@ public class StructuredTaskScope<T> implements AutoCloseable {
                 T r = (T) result;
                 return r;
             }
-            throw new IllegalStateException("Subtask not completed or did not complete successfully");
+            throw new IllegalStateException(
+                    "Result is unavailable or subtask did not complete successfully");
         }
 
         @Override
@@ -949,7 +947,8 @@ public class StructuredTaskScope<T> implements AutoCloseable {
             if (result instanceof AltResult alt && alt.state() == State.FAILED) {
                 return alt.exception();
             }
-            throw new IllegalStateException("Subtask not completed or did not complete with exception");
+            throw new IllegalStateException(
+                    "Exception is unavailable or subtask did not complete with exception");
         }
 
         @Override
diff --git a/test/jdk/java/util/concurrent/StructuredTaskScope/StructuredTaskScopeTest.java b/test/jdk/java/util/concurrent/StructuredTaskScope/StructuredTaskScopeTest.java
index 11e3f70b3ed..5ed7af8c46b 100644
--- a/test/jdk/java/util/concurrent/StructuredTaskScope/StructuredTaskScopeTest.java
+++ b/test/jdk/java/util/concurrent/StructuredTaskScope/StructuredTaskScopeTest.java
@@ -279,6 +279,7 @@ class StructuredTaskScopeTest {
                 executed.set(true);
                 return null;
             });
+            scope.join();
             assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
             assertThrows(IllegalStateException.class, subtask::get);
             assertThrows(IllegalStateException.class, subtask::exception);
@@ -673,22 +674,6 @@ class StructuredTaskScopeTest {
         }
     }
 
-    /**
-     * Test that shutdown prevents new threads from starting.
-     */
-    @Test
-    void testShutdownWithFork() throws Exception {
-        ThreadFactory factory = task -> null;
-        try (var scope = new StructuredTaskScope<Object>(null, factory)) {
-            scope.shutdown();
-            // should not invoke the ThreadFactory to create thread
-            Subtask<Void> subtask = scope.fork(() -> null);
-            assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
-            assertThrows(IllegalStateException.class, subtask::get);
-            assertThrows(IllegalStateException.class, subtask::exception);
-        }
-    }
-
     /**
      * Test that shutdown interrupts unfinished subtasks.
      */
@@ -1377,6 +1362,7 @@ class StructuredTaskScopeTest {
 
             // fork after shutdown
             Subtask<Void> subtask = scope.fork(task);
+            scope.join();
             assertEquals(task, subtask.task());
             assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
             assertThrows(IllegalStateException.class, subtask::get);