diff --git a/engine/progdefs.h b/engine/progdefs.h
index 5e5404398..db247a58f 100644
--- a/engine/progdefs.h
+++ b/engine/progdefs.h
@@ -16,6 +16,8 @@
 #ifndef PROGDEFS_H
 #define PROGDEFS_H
 
+#include "const.h"
+
 typedef struct
 {	
 	float		time;
diff --git a/server/cbase.h b/server/cbase.h
index 86ab42c4a..1c34a459c 100644
--- a/server/cbase.h
+++ b/server/cbase.h
@@ -26,6 +26,8 @@ CBaseEntity
 				CBaseGroup
 */
 #pragma once
+#include "util.h"
+
 #define	MAX_PATH_SIZE	10 // max number of nodes available for a path.
 
 // These are caps bits to indicate what an object's capabilities (currently used for save/restore and level transitions)
diff --git a/server/enginecallback.h b/server/enginecallback.h
index 5875d33a4..4a45ddd11 100644
--- a/server/enginecallback.h
+++ b/server/enginecallback.h
@@ -16,6 +16,8 @@
 #define ENGINECALLBACK_H
 #pragma once
 
+#include "edict.h"
+#include "eiface.h"
 #include "event_flags.h"
 
 // Must be provided by user of this code
diff --git a/server/saverestore.h b/server/saverestore.h
index 84da6e47e..842c4d647 100644
--- a/server/saverestore.h
+++ b/server/saverestore.h
@@ -16,6 +16,8 @@
 #ifndef SAVERESTORE_H
 #define SAVERESTORE_H
 
+#include "eiface.h"
+
 class CBaseEntity;
 
 class CSaveRestoreBuffer
diff --git a/server/util.h b/server/util.h
index 353833936..e1a764f20 100644
--- a/server/util.h
+++ b/server/util.h
@@ -29,7 +29,7 @@
 
 #include "datamap.h"
 #include "xashxt_strings.h"
-
+#include "extdll.h"
 #include "com_model.h"
 #include "sprite.h"