diff --git a/blocks_vertical/procedures.js b/blocks_vertical/procedures.js
index 7734c80b5c..85a0679d25 100644
--- a/blocks_vertical/procedures.js
+++ b/blocks_vertical/procedures.js
@@ -296,7 +296,7 @@ Blockly.ScratchBlocks.ProcedureUtils.createIcon_ = function() {
 Blockly.ScratchBlocks.ProcedureUtils.createAllInputs_ = function(connectionMap) {
   this.createIcon_()
   // Split the proc into components, by %n, %b, and %s (ignoring escaped).
-  var procComponents = this.procCode_.split(/(?=[^\\]%[nbs])/);
+  var procComponents = this.procCode_.split(/(?=[^\\]%[nsbc])/);
   procComponents = procComponents.map(function(c) {
     return c.trim(); // Strip whitespace.
   });