diff --git a/util/test/demos/vk/vk_groupshared.cpp b/util/test/demos/vk/vk_groupshared.cpp
index 95311cc39..59b0ae98d 100644
--- a/util/test/demos/vk/vk_groupshared.cpp
+++ b/util/test/demos/vk/vk_groupshared.cpp
@@ -51,6 +51,8 @@ layout(binding = 1, std430) buffer outdataBuf
 shared float gsmData[MAX_THREADS];
 shared int gsmIntData[MAX_THREADS];
 shared int gInt;
+shared float gsmSmallArray[MAX_THREADS];
+shared vec3 gsmSmall2DArray[3][MAX_THREADS];
 
 #define IsTest(x) (push.test == x)
 
@@ -266,6 +268,31 @@ void main()
     GroupMemoryBarrierWithGroupSync();
     outval.w = gInt;
   }
+  else if (IsTest(13))
+  {
+    // Out of bounds GSM access should not crash
+    uint idx = gid.x;
+    uint oneu = (idx+1)/(idx+1);
+    uint zerou = oneu - 1;
+    uint idxOOB = idx * 2 + MAX_THREADS * oneu;
+
+    gsmSmallArray[idx] = float(gid.x);
+    gsmSmall2DArray[zerou][idx].x = float(gid.x);
+    gsmSmall2DArray[zerou][idx].y = float(gid.x) + 1.0;
+    gsmSmall2DArray[oneu][idx].x = float(gid.x);
+    gsmSmall2DArray[oneu][idx].y = float(gid.x) + 1.0;
+    gsmSmall2DArray[oneu+oneu][idx].x = float(gid.x);
+    gsmSmall2DArray[oneu+oneu][idx].y = float(gid.x) + 1.0;
+
+    gsmSmallArray[idxOOB] += float(zerou);
+    gsmSmall2DArray[oneu][idxOOB].x += float(zerou);
+    gsmSmall2DArray[oneu][idxOOB].y += float(zerou);
+
+    outval.x = gsmSmallArray[idx + zerou];
+    outval.y = gsmSmallArray[idx + zerou];
+    outval.z = gsmSmall2DArray[oneu][idx + zerou].x;
+    outval.w = gsmSmall2DArray[oneu][idx + zerou].y;
+  }
 
   outdata[gid.x] = outval;
 }