diff --git a/src/assoc.h b/src/assoc.h
index 06b0fedb..05158958 100644
--- a/src/assoc.h
+++ b/src/assoc.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				assoc.h
 *
@@ -26,9 +27,7 @@
 *
 *%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
-#ifndef _FITSWCS_H_
 #include        "fitswcs.h"
-#endif
 
 #define		ASSOC_BUFINC	131072	/* Assoc buffer increment (bytes) */
 
diff --git a/src/astrom.h b/src/astrom.h
index 5711cf26..cfd2f203 100644
--- a/src/astrom.h
+++ b/src/astrom.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				astrom.h
 *
@@ -26,9 +27,7 @@
 *
 *%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
-#ifndef _FITSWCS_H_
 #include "fitswcs.h"
-#endif
 
 /*----------------------------- Internal constants --------------------------*/
 
diff --git a/src/back.h b/src/back.h
index cd536a49..70974d42 100644
--- a/src/back.h
+++ b/src/back.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				back.h
 *
diff --git a/src/bpro.h b/src/bpro.h
index 3c0f7e04..e4218ae9 100644
--- a/src/bpro.h
+++ b/src/bpro.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				bpro.h
 *
diff --git a/src/check.h b/src/check.h
index 7bf7cd62..ce8e2d1c 100644
--- a/src/check.h
+++ b/src/check.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				check.h
 *
@@ -26,9 +27,7 @@
 *
 *%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
-#ifndef _FITSCAT_H_
 #include "fits/fitscat.h"
-#endif
 
 /*----------------------------- Internal constants --------------------------*/
 
diff --git a/src/clean.h b/src/clean.h
index 058f681d..d05ba76f 100644
--- a/src/clean.h
+++ b/src/clean.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				clean.h
 *
diff --git a/src/define.h b/src/define.h
index 22653bbe..70cdcce0 100644
--- a/src/define.h
+++ b/src/define.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				define.h
 *
diff --git a/src/dgeo.h b/src/dgeo.h
index 3d30b5e0..79a5b93e 100644
--- a/src/dgeo.h
+++ b/src/dgeo.h
@@ -1,3 +1,4 @@
+#pragma once
 /**
 * @file         dgeo.h
 * @brief        Include file for dgeo.c.
@@ -24,12 +25,7 @@
 *
 *%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
-#ifndef _DGEO_H_
-#define _DGEO_H_
-
 //----------------------------- Internal constants ----------------------------
 //------------------------------- functions -----------------------------------
 extern int	dgeo_copy(picstruct *dgeofield, PIXTYPE *destx, PIXTYPE *desty,
 		int w,int h, int ix,int iy);
-
-#endif
diff --git a/src/extract.h b/src/extract.h
index 9e31b56b..b7a29e19 100644
--- a/src/extract.h
+++ b/src/extract.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				extract.h
 *
diff --git a/src/fft.h b/src/fft.h
index 1e33af6f..7e931db0 100644
--- a/src/fft.h
+++ b/src/fft.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				fft.h
 *
@@ -26,13 +27,9 @@
 *
 *%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
-#ifndef _FITSCAT_H_
 #include "fits/fitscat.h"
-#endif
 
-#ifndef FFTW3_H
-#include FFTW_H
-#endif
+#include <fftw3.h>
 
 /*---------------------------- Internal constants ---------------------------*/
 
diff --git a/src/field.h b/src/field.h
index 76c83dfe..e2bbf43d 100644
--- a/src/field.h
+++ b/src/field.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				field.h
 *
diff --git a/src/filter.h b/src/filter.h
index aebda3c8..b1d19164 100644
--- a/src/filter.h
+++ b/src/filter.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				filter.h
 *
diff --git a/src/fits/fitscat.h b/src/fits/fitscat.h
index 63bb1c7f..c038ac54 100644
--- a/src/fits/fitscat.h
+++ b/src/fits/fitscat.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				fitscat.h
 *
@@ -27,9 +28,6 @@
 *
 *%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
-#ifndef _FITSCAT_H_
-#define _FITSCAT_H_
-
 #include <stdio.h>
 
 #ifdef HAVE_SYS_TYPES_H
@@ -345,5 +343,3 @@ extern FLAGTYPE	*alloc_ibody(tabstruct *tab,
 			void (*func)(FLAGTYPE *ptr, int npix));
 
 extern t_type	ttypeof(char *str);
-
-#endif
diff --git a/src/fits/fitscat_defs.h b/src/fits/fitscat_defs.h
index 914a3e96..f8c4493b 100644
--- a/src/fits/fitscat_defs.h
+++ b/src/fits/fitscat_defs.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				fitscat_defs.h
 *
diff --git a/src/fitswcs.h b/src/fitswcs.h
index 55a4a6d4..2be6c34c 100644
--- a/src/fitswcs.h
+++ b/src/fitswcs.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				fitswcs.h
 *
@@ -27,9 +28,6 @@
 *
 *%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
-#ifndef _FITSWCS_H_
-#define _FITSWCS_H_
-
 /*-------------------------------- macros -----------------------------------*/
 
 /*----------------------------- Internal constants --------------------------*/
@@ -168,5 +166,3 @@ extern void		b2j(double yearobs, double alphain, double deltain,
 			range_wcs(wcsstruct *wcs),
 			wipe_wcs(tabstruct *tab),
 			write_wcs(tabstruct *tab, wcsstruct *wcs);
-
-#endif
diff --git a/src/flag.h b/src/flag.h
index c708e9bd..2019725b 100644
--- a/src/flag.h
+++ b/src/flag.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				flag.h
 *
diff --git a/src/globals.h b/src/globals.h
index cabf67b8..1f40772d 100644
--- a/src/globals.h
+++ b/src/globals.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				globals.h
 *
diff --git a/src/growth.h b/src/growth.h
index 74fa546d..d55e72d6 100644
--- a/src/growth.h
+++ b/src/growth.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				growth.h
 *
diff --git a/src/header.h b/src/header.h
index cbdb1c2f..f19d149b 100644
--- a/src/header.h
+++ b/src/header.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				header.h
 *
@@ -26,9 +27,7 @@
 *
 *%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
-#ifndef _FITSCAT_H_
 #include "fits/fitscat.h"
-#endif
 
 /*------------------------------- functions ---------------------------------*/
 extern int		read_aschead(char *filename, int frameno,
diff --git a/src/image.h b/src/image.h
index 47d35af7..63e92d0a 100644
--- a/src/image.h
+++ b/src/image.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				image.h
 *
diff --git a/src/interpolate.h b/src/interpolate.h
index 03ca7895..712aa257 100644
--- a/src/interpolate.h
+++ b/src/interpolate.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				interpolate.h
 *
diff --git a/src/key.h b/src/key.h
index 47a302b3..d4d999bb 100644
--- a/src/key.h
+++ b/src/key.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				key.h
 *
diff --git a/src/ldactoasc.h b/src/ldactoasc.h
index a083d07f..d4db4753 100644
--- a/src/ldactoasc.h
+++ b/src/ldactoasc.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				ldactoasc.h
 *
diff --git a/src/levmar/compiler.h b/src/levmar/compiler.h
index bff985fc..1000e89e 100644
--- a/src/levmar/compiler.h
+++ b/src/levmar/compiler.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				compiler.h
 *
@@ -44,9 +45,6 @@
 //
 /////////////////////////////////////////////////////////////////////////////////
 
-#ifndef _COMPILER_H_
-#define _COMPILER_H_
-
 /* note: intel's icc defines both __ICC & __INTEL_COMPILER.
  * Also, some compilers other than gcc define __GNUC__,
  * therefore gcc should be checked last
@@ -77,5 +75,3 @@
 #else
 #define LM_ISINF(x) isinf(x) // other than MSVC, ICC, GCC, let's hope this will work
 #endif
-
-#endif /* _COMPILER_H_ */
diff --git a/src/levmar/levmar.h b/src/levmar/levmar.h
index 64113f55..84d40ba2 100644
--- a/src/levmar/levmar.h
+++ b/src/levmar/levmar.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				levmar.h
 *
@@ -46,9 +47,6 @@
 ////////////////////////////////////////////////////////////////////////////////////
 */
 
-#ifndef _LEVMAR_H_
-#define _LEVMAR_H_
-
 /* Added by EB */
 #ifdef HAVE_CONFIG_H
 #include        "config.h"
@@ -431,5 +429,3 @@ extern int slevmar_outlid(float *r, int n, float thresh, float ls[2], char *outl
 #ifdef __cplusplus
 }
 #endif
-
-#endif /* _LEVMAR_H_ */
diff --git a/src/levmar/lm.h b/src/levmar/lm.h
index d380cb8f..ac98fbfe 100644
--- a/src/levmar/lm.h
+++ b/src/levmar/lm.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				lm.h
 *
@@ -25,14 +26,9 @@
 *	Last modified:		09/07/2012
 *
 *%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
-#ifndef _DEPR_LM_H_
-#define _DEPR_LM_H_
 
 #ifdef _MSC_VER
 #pragma message("lm.h is deprecated, please use levmar.h instead!")
 #else
 #error lm.h is deprecated, please use levmar.h instead!
 #endif /* _MSC_VER */
-
-#endif /* _DEPR_LM_H_ */
-
diff --git a/src/levmar/misc.h b/src/levmar/misc.h
index 5ac05c0c..640748b9 100644
--- a/src/levmar/misc.h
+++ b/src/levmar/misc.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				misc.h
 *
@@ -44,9 +45,6 @@
 //
 /////////////////////////////////////////////////////////////////////////////////
 
-#ifndef _MISC_H_
-#define _MISC_H_
-
 /* common suffix for LAPACK subroutines. Define empty in case of no prefix. */
 #define LM_LAPACK_SUFFIX _
 //#define LM_LAPACK_SUFFIX  // define empty
@@ -137,5 +135,3 @@ extern int dlevmar_chol(double *C, double *W, int m);
 #ifdef __cplusplus
 }
 #endif
-
-#endif /* _MISC_H_ */
diff --git a/src/neurro.h b/src/neurro.h
index 8ea3a0cf..e4b6fe51 100644
--- a/src/neurro.h
+++ b/src/neurro.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				neurro.h
 *
diff --git a/src/param.h b/src/param.h
index 9dd91277..7cbefe9b 100644
--- a/src/param.h
+++ b/src/param.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				param.h
 *
diff --git a/src/paramprofit.h b/src/paramprofit.h
index eaca6799..4cd29984 100644
--- a/src/paramprofit.h
+++ b/src/paramprofit.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				paramprofit.h
 *
diff --git a/src/pattern.h b/src/pattern.h
index 5b89f7ca..606d5f10 100644
--- a/src/pattern.h
+++ b/src/pattern.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				pattern.h
 *
@@ -26,12 +27,7 @@
 *
 *%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
-#ifndef _PROFIT_H_
 #include "profit.h"
-#endif
-
-#ifndef _PATTERN_H_
-#define _PATTERN_H_
 
 /*-------------------------------- flags ------------------------------------*/
 /*-------------------------------- macros -----------------------------------*/
@@ -87,6 +83,3 @@ void		pattern_compmodarg(patternstruct *pattern,profitstruct *profit),
 		pattern_create(patternstruct *pattern, profitstruct *profit),
 		pattern_end(patternstruct *pattern),
 		pattern_fit(patternstruct *pattern, profitstruct *profit);
-
-#endif
-
diff --git a/src/photom.h b/src/photom.h
index 4c5d0bc9..2f3996e7 100644
--- a/src/photom.h
+++ b/src/photom.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				photom.h
 *
diff --git a/src/plist.h b/src/plist.h
index 76fef18a..e2210e88 100644
--- a/src/plist.h
+++ b/src/plist.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				plist.h
 *
diff --git a/src/preflist.h b/src/preflist.h
index 985f0719..0b2dc7aa 100644
--- a/src/preflist.h
+++ b/src/preflist.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				preflist.h
 *
@@ -28,9 +29,7 @@
 
 #include "key.h"
 
-#ifndef _XML_H_
 #include "xml.h"
-#endif
 
 #ifdef  USE_THREADS
 #define THREADS_PREFMAX THREADS_NMAX
diff --git a/src/prefs.h b/src/prefs.h
index 79b016e4..48487151 100644
--- a/src/prefs.h
+++ b/src/prefs.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				prefs.h
 *
@@ -26,16 +27,9 @@
 *
 *%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
-#ifndef _PROFIT_H_
 #include        "profit.h"
-#endif
 
-#ifndef _PATTERN_H_
 #include        "pattern.h"
-#endif
-
-#ifndef _PREFS_H_
-#define _PREFS_H_
 
 /*----------------------------- Internal constants --------------------------*/
 
@@ -265,4 +259,3 @@ extern void	dumpprefs(int state),
 		preprefs(void),
 		readprefs(char *filename,char **argkey,char **argval,int narg),
 		useprefs(void);
-#endif
diff --git a/src/profit.h b/src/profit.h
index 4b05403e..3ec23754 100644
--- a/src/profit.h
+++ b/src/profit.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				profit.h
 *
@@ -26,9 +27,6 @@
 *
 *%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
-#ifndef _PROFIT_H_
-#define _PROFIT_H_
-
 /*-------------------------------- models -----------------------------------*/
 
 #define		MODEL_NONE		0x0000
@@ -269,5 +267,3 @@ void		profit_dfit(profitstruct *profit, profitstruct *dprofit,
 		profit_resetparam(profitstruct *profit, paramenum paramtype),
 		profit_resetparams(profitstruct *profit),
 		profit_surface(profitstruct *profit, obj2struct *obj2);
-
-#endif
diff --git a/src/psf.h b/src/psf.h
index befb42ed..3a47a781 100644
--- a/src/psf.h
+++ b/src/psf.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				psf.h
 *
diff --git a/src/retina.h b/src/retina.h
index cc4c3caa..706667f9 100644
--- a/src/retina.h
+++ b/src/retina.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				retina.h
 *
diff --git a/src/sexhead.h b/src/sexhead.h
index 9653cbae..8584bd56 100644
--- a/src/sexhead.h
+++ b/src/sexhead.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				sexhead.h
 *
diff --git a/src/sexhead1.h b/src/sexhead1.h
index 2834ced2..4d78abdd 100644
--- a/src/sexhead1.h
+++ b/src/sexhead1.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				sexhead1.h
 *
diff --git a/src/sexheadsc.h b/src/sexheadsc.h
index 334eec46..98dffb99 100644
--- a/src/sexheadsc.h
+++ b/src/sexheadsc.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				sexheadsc.h
 *
diff --git a/src/som.h b/src/som.h
index 4e221e83..14ce68b0 100644
--- a/src/som.h
+++ b/src/som.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				som.h
 *
diff --git a/src/threads.h b/src/threads.h
index 84ec0d3a..184e2f53 100644
--- a/src/threads.h
+++ b/src/threads.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				threads.h
 *
diff --git a/src/types.h b/src/types.h
index 56cfefe1..4849710a 100644
--- a/src/types.h
+++ b/src/types.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				types.h
 *
@@ -28,12 +29,9 @@
 
 #include <stdio.h>
 
-#ifndef _FITSCAT_H_
 #include "fits/fitscat.h"
-#endif
-#ifndef _FITSWCS_H_
+
 #include "fitswcs.h"
-#endif
 
 /*-------------------------------- flags ------------------------------------*/
 
diff --git a/src/wcs/cel.h b/src/wcs/cel.h
index dc5bb256..9061f93d 100644
--- a/src/wcs/cel.h
+++ b/src/wcs/cel.h
@@ -57,10 +57,10 @@
 *   Author: Mark Calabretta, Australia Telescope National Facility
 *   $Id: cel.h,v 1.1.1.1 2012/04/11 16:33:26 bertin Exp $
 *===========================================================================*/
- 
+
 #ifndef WCSLIB_CEL
 #define WCSLIB_CEL
-
+ 
 #include "proj.h"
 
 #ifdef __cplusplus
diff --git a/src/wcscelsys.h b/src/wcscelsys.h
index 3f62d223..9a7e149b 100644
--- a/src/wcscelsys.h
+++ b/src/wcscelsys.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				wcscelsys.h
 *
diff --git a/src/weight.h b/src/weight.h
index 111c625b..b4567dd6 100644
--- a/src/weight.h
+++ b/src/weight.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				weight.h
 *
diff --git a/src/winpos.h b/src/winpos.h
index 5dd5f176..586403f1 100644
--- a/src/winpos.h
+++ b/src/winpos.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				winpos.h
 *
diff --git a/src/xml.h b/src/xml.h
index 43feab72..27752dad 100644
--- a/src/xml.h
+++ b/src/xml.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 *				xml.h
 *
@@ -30,9 +31,7 @@
 #include	"config.h"
 #endif
 
-#ifndef _FITSCAT_H_
 #include "fits/fitscat.h"
-#endif
 
 /*----------------------------- Internal constants --------------------------*/
 #ifndef XSL_URL