diff --git a/src/jdk.jshell/share/classes/jdk/jshell/execution/ExecutionControlForwarder.java b/src/jdk.jshell/share/classes/jdk/jshell/execution/ExecutionControlForwarder.java
index 061e548878b8e..fdb126f93ec96 100644
--- a/src/jdk.jshell/share/classes/jdk/jshell/execution/ExecutionControlForwarder.java
+++ b/src/jdk.jshell/share/classes/jdk/jshell/execution/ExecutionControlForwarder.java
@@ -57,6 +57,10 @@ class ExecutionControlForwarder {
      */
     private static final int MAX_UTF_CHARS = 21844;
 
+    private static final int TRUNCATE_END = MAX_UTF_CHARS / 3;
+    private static final String TRUNCATE_JOIN = " ... ";
+    private static final int TRUNCATE_START = MAX_UTF_CHARS - TRUNCATE_JOIN.length() - TRUNCATE_END;
+
     private final ExecutionControl ec;
     private final ObjectInput in;
     private final ObjectOutput out;
@@ -108,7 +112,7 @@ private void writeUTF(String s) throws IOException {
             s = "";
         } else if (s.length() > MAX_UTF_CHARS) {
             // Truncate extremely long strings to prevent writeUTF from crashing the VM
-            s = s.substring(0, MAX_UTF_CHARS);
+            s = s.substring(0, TRUNCATE_START) + TRUNCATE_JOIN + s.substring(s.length() - TRUNCATE_END);
         }
         out.writeUTF(s);
     }
diff --git a/test/langtools/jdk/jshell/ToolFormatTest.java b/test/langtools/jdk/jshell/ToolFormatTest.java
index 84ed32e91bd3c..3aaf5e79ea5f0 100644
--- a/test/langtools/jdk/jshell/ToolFormatTest.java
+++ b/test/langtools/jdk/jshell/ToolFormatTest.java
@@ -23,7 +23,7 @@
 
 /*
  * @test
- * @bug 8148316 8148317 8151755 8152246 8153551 8154812 8157261 8163840 8166637 8161969 8173007
+ * @bug 8148316 8148317 8151755 8152246 8153551 8154812 8157261 8163840 8166637 8161969 8173007 8299829
  * @summary Tests for output customization
  * @library /tools/lib
  * @modules jdk.compiler/com.sun.tools.javac.api
@@ -300,7 +300,8 @@ public void testSetTruncation() {
                     (a) -> assertCommand(a, "/var", "|    String s = \"ABACABADA"),
                     (a) -> assertCommand(a, "String r = s", "String:\"ABACABAD ... BAXYZ\""),
                     (a) -> assertCommand(a, "r", "String:\"ABACABADA"),
-                    (a) -> assertCommand(a, "r=s", "String:\"AB")
+                    (a) -> assertCommand(a, "r=s", "String:\"AB"),
+                    (a) -> assertCommand(a, "\"0\".repeat(49999)+\"2\"", "String:\"00000000 ... 00002\"")
             );
         } finally {
             assertCommandCheckOutput(false, "/set feedback normal", s -> {