diff --git a/source/cl_cam.c b/source/cl_cam.c
index b37bd69..abe7d18 100644
--- a/source/cl_cam.c
+++ b/source/cl_cam.c
@@ -34,6 +34,15 @@
 #ifdef HAVE_CONFIG_H
 # include <config.h>
 #endif
+
+#include <math.h>
+#ifdef HAVE_STRING_H
+#include <string.h>
+#endif
+#ifdef HAVE_STRINGS_H
+#include <strings.h>
+#endif
+
 #include "cvar.h"
 #include "client.h"
 #include "pmove.h"
@@ -42,8 +51,6 @@
 #include "console.h"
 #include "commdef.h"
 
-#include <math.h>
-
 #define	PM_SPECTATORMAXSPEED	500
 #define	PM_STOPSPEED	100
 #define	PM_MAXSPEED			320
diff --git a/source/gl_model_alias.c b/source/gl_model_alias.c
index 4df7783..9edeeb1 100644
--- a/source/gl_model_alias.c
+++ b/source/gl_model_alias.c
@@ -33,6 +33,13 @@
 # include <config.h>
 #endif
 
+#ifdef HAVE_STRING_H
+#include <string.h>
+#endif
+#ifdef HAVE_STRINGS_H
+#include <strings.h>
+#endif
+
 #include "model.h"
 #include "qendian.h"
 #include "server.h"
diff --git a/source/gl_model_sprite.c b/source/gl_model_sprite.c
index b9db91a..aee384a 100644
--- a/source/gl_model_sprite.c
+++ b/source/gl_model_sprite.c
@@ -33,6 +33,13 @@
 # include <config.h>
 #endif
 
+#ifdef HAVE_STRING_H
+#include <string.h>
+#endif
+#ifdef HAVE_STRINGS_H
+#include <strings.h>
+#endif
+
 #include "model.h"
 #include "qendian.h"
 #include "glquake.h"
diff --git a/source/model.c b/source/model.c
index 225d426..e6e25d6 100644
--- a/source/model.c
+++ b/source/model.c
@@ -33,6 +33,13 @@
 # include <config.h>
 #endif
 
+#ifdef HAVE_STRING_H
+#include <string.h>
+#endif
+#ifdef HAVE_STRINGS_H
+#include <strings.h>
+#endif
+
 #include "model.h"
 #include "quakefs.h"
 #include "cvar.h"
diff --git a/source/model_alias.c b/source/model_alias.c
index bb15d82..b57a645 100644
--- a/source/model_alias.c
+++ b/source/model_alias.c
@@ -33,6 +33,13 @@
 # include <config.h>
 #endif
 
+#ifdef HAVE_STRING_H
+#include <string.h>
+#endif
+#ifdef HAVE_STRINGS_H
+#include <strings.h>
+#endif
+
 #include "r_local.h"
 #include "sys.h"
 #include "console.h"
diff --git a/source/msg.c b/source/msg.c
index 2297c82..bf41d66 100644
--- a/source/msg.c
+++ b/source/msg.c
@@ -29,6 +29,14 @@
 #ifdef HAVE_CONFIG_H
 # include <config.h>
 #endif
+
+#ifdef HAVE_STRING_H
+#include <string.h>
+#endif
+#ifdef HAVE_STRINGS_H
+#include <strings.h>
+#endif
+
 #include "msg.h"
 #include "net.h"
 #include "protocol.h"
diff --git a/source/sizebuf.c b/source/sizebuf.c
index a5c9526..6fc4201 100644
--- a/source/sizebuf.c
+++ b/source/sizebuf.c
@@ -29,6 +29,14 @@
 #ifdef HAVE_CONFIG_H
 # include "config.h"
 #endif
+
+#ifdef HAVE_STRING_H
+#include <string.h>
+#endif
+#ifdef HAVE_STRINGS_H
+#include <strings.h>
+#endif
+
 #include "sizebuf.h"
 #include "sys.h"
 
diff --git a/source/wad.c b/source/wad.c
index 7710991..79a1ab6 100644
--- a/source/wad.c
+++ b/source/wad.c
@@ -29,6 +29,14 @@
 #ifdef HAVE_CONFIG_H
 # include <config.h>
 #endif
+
+#ifdef HAVE_STRING_H
+#include <string.h>
+#endif
+#ifdef HAVE_STRINGS_H
+#include <strings.h>
+#endif
+
 #include "sys.h"
 #include "wad.h"
 #include "quakefs.h"