diff --git a/src/lib/dhcp/pkt_filter_lpf.cc b/src/lib/dhcp/pkt_filter_lpf.cc
index 0b57b21bb9..ca700c47cf 100644
--- a/src/lib/dhcp/pkt_filter_lpf.cc
+++ b/src/lib/dhcp/pkt_filter_lpf.cc
@@ -197,8 +197,7 @@ PktFilterLPF::openSocket(Iface& iface,
                   << "' to interface '" << iface.getName() << "'");
     }
 
-    // Set socket to non-blocking mode. In theory it is useless but
-    // in real world the socket can block on read...
+    // Set socket to non-blocking mode.
     if (fcntl(sock, F_SETFL, O_NONBLOCK) != 0) {
         // Get the error message immediately after the bind because the
         // invocation to close() below would override the errno.
@@ -207,7 +206,7 @@ PktFilterLPF::openSocket(Iface& iface,
         close(fallback);
         isc_throw(SocketConfigError, "failed to set SO_NONBLOCK option on the"
                   " LPF socket '" << sock << "' to interface '"
-                  << iface.getName() << "'");
+                  << iface.getName() << "'" << ", reason: " << errmsg);
     }
 
     return (SocketInfo(addr, port, sock, fallback));
diff --git a/src/lib/dhcp/tests/libdhcp++_unittest.cc b/src/lib/dhcp/tests/libdhcp++_unittest.cc
index 94648da699..95f0540de0 100644
--- a/src/lib/dhcp/tests/libdhcp++_unittest.cc
+++ b/src/lib/dhcp/tests/libdhcp++_unittest.cc
@@ -1129,9 +1129,7 @@ TEST_F(LibDhcpTest, option43Pad) {
     // Parse options.
     OptionCollection options;
     list<uint16_t> deferred;
-    size_t offset = 0;
-    ASSERT_NO_THROW(offset = LibDHCP::unpackOptions4(buf, space,
-                                                     options, deferred, true));
+    ASSERT_NO_THROW(LibDHCP::unpackOptions4(buf, space, options, deferred, true));
 
     // There should be 2 suboptions (1 and 2) because no sub-option 0
     // was defined so code 0 means PAD.
@@ -1159,9 +1157,7 @@ TEST_F(LibDhcpTest, option43Pad) {
     LibDHCP::commitRuntimeOptionDefs();
 
     options.clear();
-    offset = 0;
-    ASSERT_NO_THROW(offset = LibDHCP::unpackOptions4(buf, space,
-                                                     options, deferred, true));
+    ASSERT_NO_THROW(LibDHCP::unpackOptions4(buf, space, options, deferred, true));
 
     // There should be 2 suboptions (0 and 1).
     EXPECT_EQ(2, options.size());