diff --git a/FPEngine.h b/FPEngine.h
index 7b7200dd0..241fb3078 100644
--- a/FPEngine.h
+++ b/FPEngine.h
@@ -129,7 +129,6 @@
 
 #include "nsock.h"
 #include <vector>
-#include "osscan.h"
 #include "libnetutil/npacket.h"
 
 /* Mention some classes here so we don't have to place the declarations in
@@ -140,6 +139,7 @@ class FPProbe;
 
 class Target;
 class FingerPrintResultsIPv6;
+class FingerMatch;
 
 /******************************************************************************
  * CONSTANT DEFINITIONS                                                       *
diff --git a/FingerPrintResults.h b/FingerPrintResults.h
index f8b0d2ff8..fc4d72dfc 100644
--- a/FingerPrintResults.h
+++ b/FingerPrintResults.h
@@ -129,6 +129,7 @@
 class FingerPrintResults;
 
 #include "FPEngine.h"
+#include "osscan.h"
 
 /* Maximum number of results allowed in one of these things ... */
 #define MAX_FP_RESULTS 36
diff --git a/NmapOps.cc b/NmapOps.cc
index b8943fc11..b6ff244e5 100644
--- a/NmapOps.cc
+++ b/NmapOps.cc
@@ -125,6 +125,7 @@
 #include "nmap.h"
 #include "nbase.h"
 #include "NmapOps.h"
+#include "osscan.h"
 #include "services.h"
 #include "nmap_error.h"
 #ifdef WIN32
diff --git a/NmapOps.h b/NmapOps.h
index 405c31562..fb13f4d6a 100644
--- a/NmapOps.h
+++ b/NmapOps.h
@@ -126,10 +126,14 @@
 #ifndef NMAP_OPS_H
 #define NMAP_OPS_H
 
-#include "osscan.h" /* FingerPrintDB */
+#include "nmap.h"
 #include "output.h"
 #include <nsock.h>
 #include <string>
+#include <map>
+
+class FingerPrintDB;
+class FingerMatch;
 
 class NmapOps {
  public:
diff --git a/Target.h b/Target.h
index 7035a5df6..97f042651 100644
--- a/Target.h
+++ b/Target.h
@@ -137,8 +137,8 @@
 
 #include "portreasons.h"
 #include "portlist.h"
-#include "tcpip.h"
 #include "scan_engine.h"
+#include "osscan.h"
 #include "osscan2.h"
 class FingerPrintResults;
 
diff --git a/nse_nsock.h b/nse_nsock.h
index 614f71a1e..2c6fcf5bd 100644
--- a/nse_nsock.h
+++ b/nse_nsock.h
@@ -1,7 +1,9 @@
 #ifndef NMAP_LUA_NSOCK_H
 #define NMAP_LUA_NSOCK_H
 
-#include "nse_main.h"
+extern "C" {
+  #include "lua.h"
+}
 
 LUALIB_API int luaopen_nsock (lua_State *);
 
diff --git a/nse_utility.h b/nse_utility.h
index 0c125c5dc..affb3a056 100644
--- a/nse_utility.h
+++ b/nse_utility.h
@@ -1,7 +1,8 @@
 #ifndef NMAP_NSE_UTILITY_H
 #define NMAP_NSE_UTILITY_H
 
-#include "portlist.h"
+class Port;
+class Target;
 
 #if HAVE_STDINT_H
 #include <stdint.h>
diff --git a/osscan2.h b/osscan2.h
index 2d6b1b8fb..2f7ecd441 100644
--- a/osscan2.h
+++ b/osscan2.h
@@ -133,8 +133,10 @@
 #include <vector>
 #include <list>
 #include "timing.h"
-#include "osscan.h"
 #include "tcpip.h"
+class FingerPrint;
+class FingerTest;
+class FingerPrintResultsIPv4;
 class Target;
 
 
diff --git a/output.h b/output.h
index 52b23bd70..114439c93 100644
--- a/output.h
+++ b/output.h
@@ -162,8 +162,12 @@
  "think Solaris can support advanced localhost scans.  You can probably "\
  "use \"-Pn -sT localhost\" though.\n\n"
 
-#include "portlist.h"
+#include "nmap.h"
+#ifndef NOLUA
+#include "nse_main.h"
+#endif
 #include <nsock.h>
+class PortList;
 
 #include <stdarg.h>
 #include <string>
diff --git a/targets.cc b/targets.cc
index a2b3de65d..38c1f819f 100644
--- a/targets.cc
+++ b/targets.cc
@@ -340,6 +340,11 @@ static bool target_needs_new_hostgroup(const HostGroupState *hs, const Target *t
   return false;
 }
 
+TargetGroup::~TargetGroup() {
+  if (this->netblock != NULL)
+    delete this->netblock;
+}
+
 /* Initializes (or reinitializes) the object with a new expression, such
    as 192.168.0.0/16 , 10.1.0-5.1-254 , or fe80::202:e3ff:fe14:1102 .
    Returns 0 for success */
diff --git a/targets.h b/targets.h
index 864120e34..157fecbbf 100644
--- a/targets.h
+++ b/targets.h
@@ -126,8 +126,8 @@
 #ifndef TARGETS_H
 #define TARGETS_H
 
-#include "TargetGroup.h"
-
+#include <list>
+class NetBlock;
 class Target;
 
 class TargetGroup {
@@ -138,10 +138,7 @@ public:
     this->netblock = NULL;
   }
 
-  ~TargetGroup() {
-    if (this->netblock != NULL)
-      delete this->netblock;
-  }
+  ~TargetGroup();
 
   /* Initializes (or reinitializes) the object with a new expression,
      such as 192.168.0.0/16 , 10.1.0-5.1-254 , or