diff --git a/src/iosource/Packet.cc b/src/iosource/Packet.cc
index 2a8c39ab8a..48f9bc4f3f 100644
--- a/src/iosource/Packet.cc
+++ b/src/iosource/Packet.cc
@@ -43,16 +43,16 @@ void Packet::Init(int arg_link_type, pkt_timeval *arg_ts, uint32_t arg_caplen,
 
 	time = ts.tv_sec + double(ts.tv_usec) / 1e6;
 	hdr_size = GetLinkHeaderSize(arg_link_type);
-	l3_proto = L3_UNKNOWN;
 	eth_type = 0;
 	vlan = 0;
 	inner_vlan = 0;
-	l2_src = 0;
-	l2_dst = 0;
 
+	l2_src = nullptr;
+	l2_dst = nullptr;
 	l2_valid = false;
-
 	l2_checksummed = false;
+
+	l3_proto = L3_UNKNOWN;
 	l3_checksummed = false;
 
 	if ( data && cap_len < hdr_size )
diff --git a/src/iosource/Packet.h b/src/iosource/Packet.h
index be6d6d0f7f..70a745383a 100644
--- a/src/iosource/Packet.h
+++ b/src/iosource/Packet.h
@@ -19,12 +19,14 @@ class RecordVal;
 
 /**
  * The Layer 3 type of a packet, as determined by the parsing code in Packet.
+ * This enum is sized as an int32_t to make the Packet structure align
+ * correctly.
  */
-enum Layer3Proto {
+enum Layer3Proto : int32_t {
 	L3_UNKNOWN = -1,	/// Layer 3 type could not be determined.
-	L3_IPV4 = 1,	/// Layer 3 is IPv4.
-	L3_IPV6 = 2,	/// Layer 3 is IPv6.
-	L3_ARP = 3,	/// Layer 3 is ARP.
+	L3_IPV4 = 1,		/// Layer 3 is IPv4.
+	L3_IPV6 = 2,		/// Layer 3 is IPv6.
+	L3_ARP = 3,			/// Layer 3 is ARP.
 };
 
 /**
@@ -110,7 +112,7 @@ public:
 	 * Returns true if parsing the layer 2 fields failed, including when
 	 * no data was passed into the constructor in the first place.
 	 */
-	bool Layer2Valid()
+	bool Layer2Valid() const
 		{
 		return l2_valid;
 		}
@@ -212,14 +214,14 @@ public:
 	bool l3_checksummed;
 
 private:
-	// Calculate layer 2 attributes. Sets
+	// Calculate layer 2 attributes.
 	void ProcessLayer2();
 
 	// Wrapper to generate a packet-level weird.
 	void Weird(const char* name);
 
 	// Renders an MAC address into its ASCII representation.
-	Val *FmtEUI48(const u_char *mac) const;
+	Val* FmtEUI48(const u_char *mac) const;
 
 	// True if we need to delete associated packet memory upon
 	// destruction.