diff --git a/src/vim9.h b/src/vim9.h
index 259bdb9..10f983c 100644
--- a/src/vim9.h
+++ b/src/vim9.h
@@ -124,6 +124,7 @@
     ISN_CHECKTYPE,  // check value type is isn_arg.type.tc_type
     ISN_CHECKLEN,   // check list length is isn_arg.checklen.cl_min_len
 
+    ISN_SHUFFLE,    // move item on stack up or down
     ISN_DROP	    // pop stack and discard value
 } isntype_T;
 
@@ -237,6 +238,12 @@
     int		cl_more_OK;	// longer is allowed
 } checklen_T;
 
+// arguments to ISN_SHUFFLE
+typedef struct {
+    int		shfl_item;	// item to move (relative to top of stack)
+    int		shfl_up;	// places to move upwards
+} shuffle_T;
+
 /*
  * Instruction
  */
@@ -270,6 +277,7 @@
 	unlet_T		    unlet;
 	funcref_T	    funcref;
 	checklen_T	    checklen;
+	shuffle_T	    shuffle;
     } isn_arg;
 };