diff --git a/src/extensions/scratch3_ev3/index.js b/src/extensions/scratch3_ev3/index.js
index cd9513baa..4bea1bb17 100644
--- a/src/extensions/scratch3_ev3/index.js
+++ b/src/extensions/scratch3_ev3/index.js
@@ -79,7 +79,8 @@ const Ev3ByteValue = {
     NUM8: 0x81, // = 0b1000-001 = 1 byte to follow
     NUM16: 0x82, // = 0b1000-010 = 2 bytes to follow
     NUM32: 0x83, // = 0b1000-011 = 4 bytes to follow
-    GLOBAL8: 0xE1 // = 0b1110-001 = size of global var - 1 byte to follow
+    GLOBAL8: 0xE1, // = 0b1110-001 = size of global var - 1 byte to follow
+    GLOBAL_INDEX_0: 0x20 // = 0b00100000 = global var index "0"
 };
 
 /**
@@ -738,7 +739,7 @@ class EV3 {
             cmds[2] = 33; // 0x21 ARRAY // TODO: document
             cmds[3] = 96; // 0x60 CHANGED // TODO: document
             cmds[4] = Ev3ByteValue.GLOBAL8;
-            cmds[5] = 32; // 0x20 global var index "0" 0b00100000 // TODO: document
+            cmds[5] = Ev3ByteValue.GLOBAL_INDEX_0;
 
             // Command and payload lengths
             allocation = 33;