diff --git a/nifi-bootstrap/src/main/java/org/apache/nifi/bootstrap/BootstrapCodec.java b/nifi-bootstrap/src/main/java/org/apache/nifi/bootstrap/BootstrapCodec.java
index d925fa3164..e53a4c4ce6 100644
--- a/nifi-bootstrap/src/main/java/org/apache/nifi/bootstrap/BootstrapCodec.java
+++ b/nifi-bootstrap/src/main/java/org/apache/nifi/bootstrap/BootstrapCodec.java
@@ -57,7 +57,7 @@ public class BootstrapCodec {
         try {
             processRequest(cmd, args);
         } catch (final InvalidCommandException ice) {
-            throw new IOException("Received invalid command from NiFi: " + line + " : " + ice.getMessage() == null ? "" : "Details: " + ice.toString());
+            throw new IOException("Received invalid command from NiFi: " + line + (ice.getMessage() == null ? "" : " - Details: " + ice.toString()));
         }
     }