diff --git a/lib/groupmem.c b/lib/groupmem.c
index c18b5c64..c858b721 100644
--- a/lib/groupmem.c
+++ b/lib/groupmem.c
@@ -80,7 +80,7 @@ void gr_free (/*@out@*/ /*@only@*/struct group *grent)
 {
 	free (grent->gr_name);
 	if (NULL != grent->gr_passwd) {
-		memzero (grent->gr_passwd, strlen (grent->gr_passwd));
+		strzero (grent->gr_passwd);
 		free (grent->gr_passwd);
 	}
 	gr_free_members(grent);
diff --git a/lib/pwmem.c b/lib/pwmem.c
index f6aadb85..867e3f74 100644
--- a/lib/pwmem.c
+++ b/lib/pwmem.c
@@ -73,7 +73,7 @@ void pw_free (/*@out@*/ /*@only@*/struct passwd *pwent)
 	if (pwent != NULL) {
 		free (pwent->pw_name);
 		if (pwent->pw_passwd) {
-			memzero (pwent->pw_passwd, strlen (pwent->pw_passwd));
+			strzero (pwent->pw_passwd);
 			free (pwent->pw_passwd);
 		}
 		free (pwent->pw_gecos);
diff --git a/lib/sgroupio.c b/lib/sgroupio.c
index cf01de7b..871749bd 100644
--- a/lib/sgroupio.c
+++ b/lib/sgroupio.c
@@ -128,7 +128,7 @@ void sgr_free (/*@out@*/ /*@only@*/struct sgrp *sgent)
 	size_t i;
 	free (sgent->sg_name);
 	if (NULL != sgent->sg_passwd) {
-		memzero (sgent->sg_passwd, strlen (sgent->sg_passwd));
+		strzero (sgent->sg_passwd);
 		free (sgent->sg_passwd);
 	}
 	for (i = 0; NULL != sgent->sg_adm[i]; i++) {
diff --git a/lib/shadowmem.c b/lib/shadowmem.c
index 757d6026..82f99e72 100644
--- a/lib/shadowmem.c
+++ b/lib/shadowmem.c
@@ -59,7 +59,7 @@ void spw_free (/*@out@*/ /*@only@*/struct spwd *spent)
 	if (spent != NULL) {
 		free (spent->sp_namp);
 		if (NULL != spent->sp_pwdp) {
-			memzero (spent->sp_pwdp, strlen (spent->sp_pwdp));
+			strzero (spent->sp_pwdp);
 			free (spent->sp_pwdp);
 		}
 		free (spent);