1 files changed, 4 insertions, 0 deletions
diff --git a/java-compat/src/Ice/src/main/java/Ice/ConnectionI.java b/java-compat/src/Ice/src/main/java/Ice/ConnectionI.java
index 9c4c4c45e16..8b334e9db6e 100644
--- a/java-compat/src/Ice/src/main/java/Ice/ConnectionI.java
+++ b/java-compat/src/Ice/src/main/java/Ice/ConnectionI.java
@@ -701,6 +701,10 @@ public final class ConnectionI extends IceInternal.EventHandler
     synchronized public void setACM(Ice.IntOptional timeout, Ice.Optional<ACMClose> close,
             Ice.Optional<ACMHeartbeat> heartbeat)
     {
+        if(timeout != null && timeout.isSet() && timeout.get() < 0)
+        {
+            throw new IllegalArgumentException("invalid negative ACM timeout value");
+        }
         if(_monitor == null || _state >= StateClosed)
         {
             return;