diff --git a/lib/fields.c b/lib/fields.c
index 53929248..b6d2fa14 100644
--- a/lib/fields.c
+++ b/lib/fields.c
@@ -14,7 +14,10 @@
 #include <ctype.h>
 #include <string.h>
 #include <stdio.h>
+
 #include "prototypes.h"
+#include "string/strchr/strrspn.h"
+
 
 /*
  * valid_field - insure that a field contains all legal characters
@@ -89,11 +92,7 @@ void change_field (char *buf, size_t maxsize, const char *prompt)
 		 * makes it possible to change the field to empty, by
 		 * entering a space.  --marekm
 		 */
-
-		while (newf < cp && isspace (cp[-1])) {
-			cp--;
-		}
-		*cp = '\0';
+		*strrspn(newf, " \t\n") = '\0';
 
 		cp = newf;
 		while (isspace (*cp)) {
diff --git a/lib/getdef.c b/lib/getdef.c
index 459fdc99..91f40702 100644
--- a/lib/getdef.c
+++ b/lib/getdef.c
@@ -31,6 +31,7 @@
 #include "string/sprintf/xasprintf.h"
 #include "string/strchr/stpcspn.h"
 #include "string/strchr/stpspn.h"
+#include "string/strchr/strrspn.h"
 
 
 /*
@@ -528,7 +529,6 @@ static void def_load (void)
 #else /* USE_ECONF */
 static void def_load (void)
 {
-	int i;
 	FILE *fp;
 	char buf[1024], *name, *value, *s;
 
@@ -560,13 +560,7 @@ static void def_load (void)
 		/*
 		 * Trim trailing whitespace.
 		 */
-		for (i = (ptrdiff_t) strlen (buf) - 1; i >= 0; --i) {
-			if (!isspace (buf[i])) {
-				break;
-			}
-		}
-		i++;
-		buf[i] = '\0';
+		*strrspn(buf, " \t\n") = '\0';
 
 		/*
 		 * Break the line into two fields.
diff --git a/src/login_nopam.c b/src/login_nopam.c
index 1a2b1736..03a2871f 100644
--- a/src/login_nopam.c
+++ b/src/login_nopam.c
@@ -57,6 +57,7 @@
 #include <arpa/inet.h>		/* for inet_ntoa() */
 
 #include "sizeof.h"
+#include "string/strchr/strrspn.h"
 
 #if !defined(MAXHOSTNAMELEN) || (MAXHOSTNAMELEN < 64)
 #undef MAXHOSTNAMELEN
@@ -110,10 +111,7 @@ int login_access (const char *user, const char *from)
 			if (line[0] == '#') {
 				continue;	/* comment line */
 			}
-			while (end > 0 && isspace (line[end - 1])) {
-				end--;
-			}
-			line[end] = '\0';	/* strip trailing whitespace */
+			*strrspn(line, " \t\n") = '\0';
 			if (line[0] == '\0') {	/* skip blank lines */
 				continue;
 			}
diff --git a/src/suauth.c b/src/suauth.c
index 4d631904..ed45a856 100644
--- a/src/suauth.c
+++ b/src/suauth.c
@@ -8,13 +8,17 @@
  */
 
 #include <config.h>
+
 #include <errno.h>
 #include <grp.h>
 #include <pwd.h>
 #include <stdio.h>
 #include <sys/types.h>
+
 #include "defines.h"
 #include "prototypes.h"
+#include "string/strchr/strrspn.h"
+
 
 #ifndef SUAUTHFILE
 #define SUAUTHFILE "/etc/suauth"
@@ -77,11 +81,7 @@ int check_su_auth (const char *actual_id,
 			continue;
 		}
 
-		while (endline > 0 && (temp[endline - 1] == ' '
-				       || temp[endline - 1] == '\t'
-				       || temp[endline - 1] == '\n'))
-			endline--;
-		temp[endline] = '\0';
+		*strrspn(temp, " \t\n") = '\0';
 
 		posn = 0;
 		while (temp[posn] == ' ' || temp[posn] == '\t')