--- a/fverify.h
+++ b/fverify.h
@@ -169,16 +169,16 @@
     int  errnum;			/* number of errors in this hdu */
     int  wrnno;			/* number of warnning in this hdu */
 }HduName;    
-int get_total_warn();
-int get_total_err();
-void init_hduname();
+int get_total_warn(void);
+int get_total_err(void);
+void init_hduname(void);
 void set_hduname(int hdunum,int hdutype, char* extname,int  extver);
 void set_hduerr(int hdunum);
 void set_hdubasic(int hdunum,int hdutype);
 int test_hduname(int hdunum1, int hdunum2);
 void total_errors (int *totalerr, int * totalwrn);
 void hdus_summary(FILE *out);
-void destroy_hduname();
+void destroy_hduname(void);
 void test_end(fitsfile *infits, FILE *out);
 void init_report(FILE *out, char *rootnam);
 void close_report(FILE *out);
@@ -198,7 +198,7 @@
 int wrtserr(FILE *out, char* mess, int *status, int severity);
 void wrtsep (FILE *out,char fill, char *title, int nchar);
 void num_err_wrn(int *num_err, int *num_wrn);
-void reset_err_wrn();
+void reset_err_wrn(void);
 int compkey (const void *key1, const void *key2);
 int compcol (const void *col1, const void *col2);
 int compcol (const void *col1, const void *col2);
--- a/fvrf_file.c
+++ b/fvrf_file.c
@@ -3,17 +3,17 @@
 static int total_err=1;  /* initialzed to 1 in case fail to open file */
 static int total_warn=0;
 
-int get_total_warn()
+int get_total_warn(void)
 {
     return (total_warn);
 }
-int get_total_err()
+int get_total_err(void)
 {
     return (total_err);
 }
 
 /* Get the total hdu number and allocate the memory for hdu array */  
-void init_hduname() 
+void init_hduname(void) 
 {
     int i;
     /* allocate memories for the hdu structure array  */
@@ -168,7 +168,7 @@
 
 		   
 
-void destroy_hduname() 
+void destroy_hduname(void) 
 { 
    int i;
    for (i=0; i < totalhdu; i++) free(hduname[i]);
--- a/fvrf_misc.c
+++ b/fvrf_misc.c
@@ -20,7 +20,7 @@
     return;
 }
 
-void reset_err_wrn() 
+void reset_err_wrn(void) 
 { 
     nwrns = 0; 
     nerrs = 0;