diff --git a/src/vim9execute.c b/src/vim9execute.c
index 0fa1a12..481c94f 100644
--- a/src/vim9execute.c
+++ b/src/vim9execute.c
@@ -5487,6 +5487,9 @@
 			case JUMP_ALWAYS:
 			    when = "JUMP";
 			    break;
+			case JUMP_NEVER:
+			    iemsg("JUMP_NEVER should not be used");
+			    break;
 			case JUMP_AND_KEEP_IF_TRUE:
 			    when = "JUMP_AND_KEEP_IF_TRUE";
 			    break;