diff --git a/src/EventHandler.cc b/src/EventHandler.cc
index 2867b63437..5598f93f98 100644
--- a/src/EventHandler.cc
+++ b/src/EventHandler.cc
@@ -96,7 +96,7 @@ EventHandler* EventHandler::Unserialize(UnserialInfo* info)
 	{
 	char* name;
 	if ( ! UNSERIALIZE_STR(&name, 0) )
-		return false;
+		return 0;
 
 	EventHandler* h = event_registry->Lookup(name);
 	if ( ! h )
diff --git a/src/Func.cc b/src/Func.cc
index 30689d4c26..582de1d9bb 100644
--- a/src/Func.cc
+++ b/src/Func.cc
@@ -100,7 +100,7 @@ Func* Func::Unserialize(UnserialInfo* info)
 		if ( ! (id->HasVal() && id->ID_Val()->Type()->Tag() == TYPE_FUNC) )
 			{
 			info->s->Error(fmt("ID %s is not a built-in", name));
-			return false;
+			return 0;
 			}
 
 		Unref(f);
diff --git a/src/RemoteSerializer.h b/src/RemoteSerializer.h
index 1d7feef585..5ff7fff8d6 100644
--- a/src/RemoteSerializer.h
+++ b/src/RemoteSerializer.h
@@ -17,8 +17,8 @@
 class IncrementalSendTimer;
 
 namespace threading {
-	class Field;
-	class Value;
+	struct Field;
+	struct Value;
 }
 
 // This class handles the communication done in Bro's main loop.
diff --git a/src/SMB.cc b/src/SMB.cc
index edce2a69b8..a06707328a 100644
--- a/src/SMB.cc
+++ b/src/SMB.cc
@@ -368,7 +368,7 @@ int SMB_Session::ParseSetupAndx(int is_orig, binpac::SMB::SMB_header const& hdr,
 	// The binpac type depends on the negotiated server settings -
 	// possibly we can just pick the "right" format here, and use that?
 
-	if ( hdr.flags2() && 0x0800 )
+	if ( hdr.flags2() & 0x0800 )
 		{
 		binpac::SMB::SMB_setup_andx_ext msg(hdr.unicode());
 		msg.Parse(body.data(), body.data() + body.length());
diff --git a/src/SerialObj.cc b/src/SerialObj.cc
index a8ab969f5e..73cab275c2 100644
--- a/src/SerialObj.cc
+++ b/src/SerialObj.cc
@@ -163,7 +163,7 @@ SerialObj* SerialObj::Unserialize(UnserialInfo* info, SerialType type)
 	if ( ! result )
 		{
 		DBG_POP(DBG_SERIAL);
-		return false;
+		return 0;
 		}
 
 	DBG_POP(DBG_SERIAL);
diff --git a/src/Sessions.h b/src/Sessions.h
index a7d7b1272f..25065012e6 100644
--- a/src/Sessions.h
+++ b/src/Sessions.h
@@ -18,7 +18,7 @@ struct pcap_pkthdr;
 
 class EncapsulationStack;
 class Connection;
-class ConnID;
+struct ConnID;
 class OSFingerprint;
 class ConnCompressor;
 
diff --git a/src/Type.cc b/src/Type.cc
index caba0c9fa0..414c07d3d7 100644
--- a/src/Type.cc
+++ b/src/Type.cc
@@ -910,7 +910,7 @@ Val* RecordType::FieldDefault(int field) const
 	const TypeDecl* td = FieldDecl(field);
 
 	if ( ! td->attrs )
-		return false;
+		return 0;
 
 	const Attr* def_attr = td->attrs->FindAttr(ATTR_DEFAULT);
 
diff --git a/src/input/readers/Ascii.cc b/src/input/readers/Ascii.cc
index 1731bba872..dd1e742e5e 100644
--- a/src/input/readers/Ascii.cc
+++ b/src/input/readers/Ascii.cc
@@ -232,7 +232,7 @@ Value* Ascii::EntryToVal(string s, FieldMapping field)
 			{
 			Error(Fmt("Field: %s Invalid value for boolean: %s",
 				  field.name.c_str(), s.c_str()));
-			return false;
+			return 0;
 			}
 		break;
 
@@ -262,7 +262,7 @@ Value* Ascii::EntryToVal(string s, FieldMapping field)
 		if ( pos == s.npos )
 			{
 			Error(Fmt("Invalid value for subnet: %s", s.c_str()));
-			return false;
+			return 0;
 			}
 
 		int width = atoi(s.substr(pos+1).c_str());
diff --git a/src/logging/Manager.cc b/src/logging/Manager.cc
index 511fedc984..0fea3d577d 100644
--- a/src/logging/Manager.cc
+++ b/src/logging/Manager.cc
@@ -983,7 +983,7 @@ WriterFrontend* Manager::CreateWriter(EnumVal* id, EnumVal* writer, const Writer
 
 	if ( ! stream )
 		// Don't know this stream.
-		return false;
+		return 0;
 
 	Stream::WriterMap::iterator w =
 		stream->writers.find(Stream::WriterPathPair(writer->AsEnum(), info.path));
diff --git a/src/ssl-analyzer.pac b/src/ssl-analyzer.pac
index bf9cf1e0ba..bd4b76ee98 100644
--- a/src/ssl-analyzer.pac
+++ b/src/ssl-analyzer.pac
@@ -295,7 +295,7 @@ refine connection SSL_Conn += {
 					for ( int k = 0; k < num_ext; ++k )
 						{
 						unsigned char *pBuffer = 0;
-						uint length = 0;
+						int length = 0;
 
 						X509_EXTENSION* ex = X509_get_ext(pTemp, k);
 						if (ex)
@@ -303,7 +303,7 @@ refine connection SSL_Conn += {
 							ASN1_STRING *pString = X509_EXTENSION_get_data(ex);
 							length = ASN1_STRING_to_UTF8(&pBuffer, pString);
 							//i2t_ASN1_OBJECT(&pBuffer, length, obj)
-							// printf("extension length: %u\n", length);
+							// printf("extension length: %d\n", length);
 							// -1 indicates an error.
 							if ( length < 0 )
 								continue;
diff --git a/src/threading/SerialTypes.h b/src/threading/SerialTypes.h
index 9ce53c7cb1..283d88bf4c 100644
--- a/src/threading/SerialTypes.h
+++ b/src/threading/SerialTypes.h
@@ -2,8 +2,6 @@
 #ifndef THREADING_SERIALIZATIONTYPES_H
 #define THREADING_SERIALIZATIONTYPES_H
 
-using namespace std;
-
 #include <sys/socket.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
@@ -11,6 +9,8 @@ using namespace std;
 #include "Type.h"
 #include "net_util.h"
 
+using namespace std;
+
 class SerializationFormat;
 
 namespace threading {