diff --git a/extract/extDebugInt.h b/extract/extDebugInt.h
index 5e59284e..7e3248f8 100644
--- a/extract/extDebugInt.h
+++ b/extract/extDebugInt.h
@@ -22,6 +22,9 @@
  *
  */
 
+#ifndef _MAGIC__EXTRACT__EXTDEBUGINT_H
+#define _MAGIC__EXTRACT__EXTDEBUGINT_H
+
 extern int extDebAreaEnum;
 extern int extDebArray;
 extern int extDebHardWay;
@@ -38,3 +41,5 @@ extern int extDebPerim;
 extern int extDebResist;
 extern int extDebVisOnly;
 extern int extDebYank;
+
+#endif /* _MAGIC__EXTRACT__EXTDEBUGINT_H */
diff --git a/garouter/gaDebug.h b/garouter/gaDebug.h
index d8c5ab89..171ec75c 100644
--- a/garouter/gaDebug.h
+++ b/garouter/gaDebug.h
@@ -21,6 +21,9 @@
  * rcsid $Header: /usr/cvsroot/magic-8.0/garouter/gaDebug.h,v 1.1.1.1 2008/02/03 20:43:50 tim Exp $
  */
 
+#ifndef _MAGIC__GAROUTER__GADEBUG_H
+#define _MAGIC__GAROUTER__GADEBUG_H
+
     /* Flags */
 extern int gaDebChanOnly;
 extern int gaDebChanStats;
@@ -32,3 +35,5 @@ extern int gaDebShowMaze;
 extern int gaDebStems;
 extern int gaDebVerbose;
 extern int gaDebNoClean;
+
+#endif /* _MAGIC__GAROUTER__GADEBUG_H */
diff --git a/graphics/grOGLInt.h b/graphics/grOGLInt.h
index 7efa2cdb..77eddbd4 100644
--- a/graphics/grOGLInt.h
+++ b/graphics/grOGLInt.h
@@ -8,6 +8,9 @@
  * the X .h files.
  */
 
+#ifndef _MAGIC__GRAPHICS__GROGLINT_H
+#define _MAGIC__GRAPHICS__GROGLINT_H
+
 #include "utils/magic.h"
 
 /* Constants
@@ -93,3 +96,5 @@ extern int groglNbRects;
 #define GR_X_FLUSH_LINES() {if (groglNbLines>0) {groglDrawLines(groglLines, groglNbLines); groglNbLines=0;}}
 #define GR_X_FLUSH_RECTS() {if (groglNbRects>0) {groglFillRects(groglRects, groglNbRects); groglNbRects=0;}}
 #define	GR_X_FLUSH_BATCH() {GR_X_FLUSH_LINES(); GR_X_FLUSH_RECTS();}
+
+#endif /* _MAGIC__GRAPHICS__GROGLINT_H */
diff --git a/graphics/grTCairoInt.h b/graphics/grTCairoInt.h
index 4188ffe6..c98c8e3a 100644
--- a/graphics/grTCairoInt.h
+++ b/graphics/grTCairoInt.h
@@ -10,6 +10,9 @@
  * Copyright 2003 Open Circuit Design, Inc., for MultiGiG Ltd.
  */
 
+#ifndef _MAGIC__GRAPHICS__GRTCAIROINT_H
+#define _MAGIC__GRAPHICS__GRTCAIROINT_H
+
 #include "utils/magic.h"
 
 /* Constants
@@ -122,3 +125,5 @@ extern TCairoRect grtcairoRects[];
 
 /* Used by the wind3d window */
 extern void TCairoEventProc();
+
+#endif /* _MAGIC__GRAPHICS__GRTCAIROINT_H */
diff --git a/graphics/grTOGLInt.h b/graphics/grTOGLInt.h
index 5292dea9..88d8f3c6 100644
--- a/graphics/grTOGLInt.h
+++ b/graphics/grTOGLInt.h
@@ -10,6 +10,9 @@
  * Copyright 2003 Open Circuit Design, Inc., for MultiGiG Ltd.
  */
 
+#ifndef _MAGIC__GRAPHICS__GRTOGLINT_H
+#define _MAGIC__GRAPHICS__GRTOGLINT_H
+
 #include "utils/magic.h"
 
 /* Constants
@@ -119,3 +122,5 @@ extern TOGLRect grtoglRects[];
 
 /* Used by the wind3d window */
 extern void TOGLEventProc();
+
+#endif /* _MAGIC__GRAPHICS__GRTOGLINT_H */
diff --git a/graphics/grTkCommon.h b/graphics/grTkCommon.h
index 33aeb0be..58680b60 100644
--- a/graphics/grTkCommon.h
+++ b/graphics/grTkCommon.h
@@ -5,6 +5,9 @@
  *
  */
 
+#ifndef _MAGIC__GRAPHICS__GRTKCOMMON_H
+#define _MAGIC__GRAPHICS__GRTKCOMMON_H
+
 #define MAX_CURSORS 32
 
 #define grSmallFont     grTkFonts[0]
@@ -48,3 +51,4 @@ extern Tk_Cursor grCursors[MAX_CURSORS];
 extern Display *grXdpy;
 extern int      grXscrn;
 
+#endif /* _MAGIC__GRAPHICS__GRTKCOMMON_H */
diff --git a/graphics/grTkInt.h b/graphics/grTkInt.h
index 9ffca5e8..14e26819 100644
--- a/graphics/grTkInt.h
+++ b/graphics/grTkInt.h
@@ -10,6 +10,9 @@
  * Copyright 2003 Open Circuit Design, Inc., for MultiGiG Ltd.
  */
 
+#ifndef _MAGIC__GRAPHICS__GRTKINT_H
+#define _MAGIC__GRAPHICS__GRTKINT_H
+
 #include "utils/magic.h"
 
 /* Constants
@@ -90,3 +93,4 @@ extern int grtkNbRects;
 #define GR_TK_FLUSH_RECTS() {if (grtkNbRects>0) {grtkFillRects(grtkRects, grtkNbRects); grtkNbRects=0;}}
 #define	GR_TK_FLUSH_BATCH() {GR_TK_FLUSH_LINES(); GR_TK_FLUSH_RECTS();}
 
+#endif /* _MAGIC__GRAPHICS__GRTKINT_H */
diff --git a/graphics/grX11Int.h b/graphics/grX11Int.h
index 052eea79..2cd2d4df 100644
--- a/graphics/grX11Int.h
+++ b/graphics/grX11Int.h
@@ -8,6 +8,9 @@
  * the X .h files.
  */
 
+#ifndef _MAGIC__GRAPHICS__GRX11INT_H
+#define _MAGIC__GRAPHICS__GRX11INT_H
+
 #include "utils/magic.h"
 
 /* Constants
@@ -116,3 +119,5 @@ extern int grx11NbRects;
 #define GR_X_FLUSH_LINES() {if (grx11NbLines>0) {grx11DrawLines(grx11Lines, grx11NbLines); grx11NbLines=0;}}
 #define GR_X_FLUSH_RECTS() {if (grx11NbRects>0) {grx11FillRects(grx11Rects, grx11NbRects); grx11NbRects=0;}}
 #define	GR_X_FLUSH_BATCH() {GR_X_FLUSH_LINES(); GR_X_FLUSH_RECTS();}
+
+#endif /* _MAGIC__GRAPHICS__GRX11INT_H */
diff --git a/irouter/irDebug.h b/irouter/irDebug.h
index be66bb72..e517ed98 100644
--- a/irouter/irDebug.h
+++ b/irouter/irDebug.h
@@ -31,7 +31,12 @@
  *
  */
 
+#ifndef _MAGIC__IROUTER__IRDEBUG_H
+#define _MAGIC__IROUTER__IRDEBUG_H
+
 extern int irDebEndPts; /* traces endpoint processing */
 extern int irDebNoClean; /* doesn't cleanup after route, so data strucs
 			  * can be examined.
 			  */
+
+#endif /* _MAGIC__IROUTER__IRDEBUG_H */
diff --git a/mzrouter/mzDebug.h b/mzrouter/mzDebug.h
index 253ee3fe..ef079d97 100644
--- a/mzrouter/mzDebug.h
+++ b/mzrouter/mzDebug.h
@@ -30,8 +30,12 @@
  *
  */
 
+#ifndef _MAGIC__MZROUTER__MZDEBUG_H
+#define _MAGIC__MZROUTER__MZDEBUG_H
+
 extern int mzDebStep;	/* single step - pauses after each path extension,
 			   and prints statistics */
 extern int mzDebMaze;	/* traces maze router - details on selection of
 			   best path and extension from it. */
 
+#endif /* _MAGIC__MZROUTER__MZDEBUG_H */
diff --git a/plow/plowDebugInt.h b/plow/plowDebugInt.h
index 87472363..09a9309d 100644
--- a/plow/plowDebugInt.h
+++ b/plow/plowDebugInt.h
@@ -21,6 +21,9 @@
  * rcsid $Header: /usr/cvsroot/magic-8.0/plow/plowDebugInt.h,v 1.1.1.1 2008/02/03 20:43:50 tim Exp $
  */
 
+#ifndef _MAGIC__PLOW__PLOWDEBUGINT_H
+#define _MAGIC__PLOW__PLOWDEBUGINT_H
+
 extern int plowDebAdd;
 extern int plowDebMove;
 extern int plowDebNext;
@@ -33,3 +36,5 @@ extern ClientData plowDebugID;
 
 extern Point plowWhenTopPoint, plowWhenBotPoint;
 extern bool plowWhenTop, plowWhenBot;
+
+#endif /* _MAGIC__PLOW__PLOWDEBUGINT_H */
diff --git a/utils/geofast.h b/utils/geofast.h
index af1f3664..deb7cde4 100644
--- a/utils/geofast.h
+++ b/utils/geofast.h
@@ -24,6 +24,9 @@
 
 /* rcsid "$Header: /usr/cvsroot/magic-8.0/utils/geofast.h,v 1.1.1.1 2008/02/03 20:43:50 tim Exp $" */
 
+#ifndef _MAGIC__UTILS__GEOFAST_H
+#define _MAGIC__UTILS__GEOFAST_H
+
 /* ---------------------------- Clipping ------------------------------ */
 
 /*
@@ -187,3 +190,5 @@
 	(tresult)->t_c += tMul(x, xt->t_a) + tMul(y, xt->t_b); \
 	(tresult)->t_f += tMul(x, xt->t_d) + tMul(y, xt->t_e); \
     }
+
+#endif /* _MAGIC__UTILS__GEOFAST_H */