diff --git a/w-stacking-fftw.c b/w-stacking-fftw.c
index fc8eb047c6702cda089ad120fd175ca3edb68b0b..5469014518e9e03a3d65ee9461bccb9c58cebfc1 100644
--- a/w-stacking-fftw.c
+++ b/w-stacking-fftw.c
@@ -22,6 +22,7 @@
 #define MAX(X, Y) (((X) > (Y)) ? (X) : (Y))
 #define NOVERBOSE
 #define NFILES 100
+#define FILENAMELENGTH 30
 
 // Linked List set-up
 struct sectorlist {
@@ -51,31 +52,29 @@ int main(int argc, char * argv[])
 	// Global filename to be composed
 	char filename[1000];
 	
-	// MS paths
-	char datapath[900];
-	char datapath_multi[NFILES][900];
-
-        // Bin MS files
-	char ufile[30] = "ucoord.bin";
-        char vfile[30] = "vcoord.bin";
-        char wfile[30] = "wcoord.bin";
-        char weightsfile[30] = "weights.bin";
-        char visrealfile[30] = "visibilities_real.bin";
-        char visimgfile[30] = "visibilities_img.bin";
-        char metafile[30] = "meta.txt";
+        // MS paths
+        char datapath[900];
+        char datapath_multi[NFILES][900];
+        char ufile[FILENAMELENGTH] = "ucoord.bin";
+        char vfile[FILENAMELENGTH] = "vcoord.bin";
+        char wfile[FILENAMELENGTH] = "wcoord.bin";
+        char weightsfile[FILENAMELENGTH] = "weights.bin";
+        char visrealfile[FILENAMELENGTH] = "visibilities_real.bin";
+        char visimgfile[FILENAMELENGTH] = "visibilities_img.bin";
+        char metafile[FILENAMELENGTH] = "meta.txt";
 
         // Mesh related files 
-	char outfile[30] = "grid.txt";
-	char outfile1[30] = "coords.txt";
-	char outfile2[30] = "grid_real.bin";
-	char outfile3[30] = "grid_img.bin";
-	char fftfile[30] = "fft.txt";
-	char fftfile2[30] = "fft_real.bin";
-	char fftfile3[30] = "fft_img.bin";
-	char logfile[30] = "run.log";
-	char extension[30] = ".txt";
-	char srank[4];
-	char timingfile[30] = "timings.dat";
+        char outfile[FILENAMELENGTH] = "grid.txt";
+        char outfile1[FILENAMELENGTH] = "coords.txt";
+        char outfile2[FILENAMELENGTH] = "grid_real.bin";
+        char outfile3[FILENAMELENGTH] = "grid_img.bin";
+        char fftfile[FILENAMELENGTH] = "fft.txt";
+        char fftfile2[FILENAMELENGTH] = "fft_real.bin";
+        char fftfile3[FILENAMELENGTH] = "fft_img.bin";
+        char logfile[FILENAMELENGTH] = "run.log";
+        char extension[FILENAMELENGTH] = ".txt";
+        char srank[4];
+        char timingfile[FILENAMELENGTH] = "timings.dat";
 
 	// Visibilities related variables
 	double * uu;