diff --git a/lib/fields.c b/lib/fields.c
index ada6726e7..5900395ef 100644
--- a/lib/fields.c
+++ b/lib/fields.c
@@ -43,7 +43,7 @@ int valid_field (const char *field, const char *illegal)
 
 	/* For each character of field, search if it appears in the list
 	 * of illegal characters. */
-	if (illegal && NULL != strpbrk (field, illegal)) {
+	if (illegal && strpbrk(field, illegal)) {
 		return -1;
 	}
 
diff --git a/lib/setupenv.c b/lib/setupenv.c
index 63f7fb95d..28754b5d5 100644
--- a/lib/setupenv.c
+++ b/lib/setupenv.c
@@ -72,7 +72,7 @@ static void read_env_file (const char *filename)
 		val = stpsep(cp, "=");
 		if (val == NULL)
 			continue;
-		if (strpbrk(name, " \t") != NULL)
+		if (strpbrk(name, " \t"))
 			continue;
 #if 0				/* XXX untested, and needs rewrite with fewer goto's :-) */
 /*
diff --git a/src/useradd.c b/src/useradd.c
index 562ba44fc..e6cce57d5 100644
--- a/src/useradd.c
+++ b/src/useradd.c
@@ -109,7 +109,7 @@ static const char *def_log_init = "yes";
 static long def_inactive = -1;
 static const char *def_expire = "";
 
-#define	VALID(s)	(strcspn (s, ":\n") == strlen (s))
+#define VALID(s)  (!strpbrk(s, ":\n"))
 
 static const char *user_name = "";
 static const char *user_pass = "!";
diff --git a/src/usermod.c b/src/usermod.c
index 7ea1a7244..49159d60f 100644
--- a/src/usermod.c
+++ b/src/usermod.c
@@ -93,7 +93,7 @@
 #define E_SUB_GID_UPDATE 18	/* can't update the subordinate gid file */
 #endif				/* ENABLE_SUBIDS */
 
-#define	VALID(s)	(strcspn (s, ":\n") == strlen (s))
+#define VALID(s)  (!strpbrk(s, ":\n"))
 
 /*
  * Global variables