diff --git a/OpenCL/m01500_a3-pure.cl b/OpenCL/m01500_a3-pure.cl
index 76eedbb3d..f825cc887 100644
--- a/OpenCL/m01500_a3-pure.cl
+++ b/OpenCL/m01500_a3-pure.cl
@@ -1920,6 +1920,8 @@ KERNEL_FQ void m01500_mxx (KERN_ATTR_BITSLICE ())
   const u64 gid = get_global_id (0);
   const u64 lid = get_local_id (0);
 
+  if (gid >= gid_max) return;
+
   /**
    * salt
    */
@@ -2297,6 +2299,8 @@ KERNEL_FQ void m01500_sxx (KERN_ATTR_BITSLICE ())
   const u64 gid = get_global_id (0);
   const u64 lid = get_local_id (0);
 
+  if (gid >= gid_max) return;
+
   /**
    * salt
    */
diff --git a/OpenCL/m03000_a3-pure.cl b/OpenCL/m03000_a3-pure.cl
index 1dff1dc51..7255e5496 100644
--- a/OpenCL/m03000_a3-pure.cl
+++ b/OpenCL/m03000_a3-pure.cl
@@ -1761,6 +1761,8 @@ KERNEL_FQ void m03000_mxx (KERN_ATTR_BITSLICE ())
   const u64 gid = get_global_id (0);
   const u64 lid = get_local_id (0);
 
+  if (gid >= gid_max) return;
+
   /**
    * base
    */
@@ -2138,6 +2140,8 @@ KERNEL_FQ void m03000_sxx (KERN_ATTR_BITSLICE ())
   const u64 gid = get_global_id (0);
   const u64 lid = get_local_id (0);
 
+  if (gid >= gid_max) return;
+
   /**
    * digest
    */