diff --git a/vm/ubpf_jit.c b/vm/ubpf_jit.c
index 3d83417..0e7b10f 100644
--- a/vm/ubpf_jit.c
+++ b/vm/ubpf_jit.c
@@ -1,3 +1,6 @@
+// Copyright (c) 2015 Big Switch Networks, Inc
+// SPDX-License-Identifier: Apache-2.0
+
 /*
  * Copyright 2015 Big Switch Networks, Inc
  * Copyright 2017 Google Inc.
@@ -67,6 +70,10 @@
 
     jitted_size = 65536;
     buffer = calloc(jitted_size, 1);
+    if (buffer == NULL) {
+        *errmsg = ubpf_error("internal uBPF error: calloc failed: %s\n", strerror(errno));
+        goto out;
+    }
 
     if (ubpf_translate(vm, buffer, &jitted_size, errmsg) < 0) {
         goto out;
diff --git a/vm/ubpf_vm.c b/vm/ubpf_vm.c
index ef8778e..29063d6 100644
--- a/vm/ubpf_vm.c
+++ b/vm/ubpf_vm.c
@@ -340,12 +340,10 @@
             reg[inst.dst] &= UINT32_MAX;
             break;
         case EBPF_OP_LSH_IMM:
-            reg[inst.dst] = u32(reg[inst.dst]) << SHIFT_MASK_32_BIT(inst.imm);
-            reg[inst.dst] &= UINT32_MAX;
+            reg[inst.dst] = (u32(reg[inst.dst]) << SHIFT_MASK_32_BIT(inst.imm) & UINT32_MAX);
             break;
         case EBPF_OP_LSH_REG:
-            reg[inst.dst] = u32(reg[inst.dst]) << SHIFT_MASK_32_BIT(reg[inst.src]);
-            reg[inst.dst] &= UINT32_MAX;
+            reg[inst.dst] = (u32(reg[inst.dst]) << SHIFT_MASK_32_BIT(reg[inst.src]) & UINT32_MAX);
             break;
         case EBPF_OP_RSH_IMM:
             reg[inst.dst] = u32(reg[inst.dst]) >> SHIFT_MASK_32_BIT(inst.imm);