diff --git a/usr.bin/localedef/charmap.c b/usr.bin/localedef/charmap.c
--- a/usr.bin/localedef/charmap.c
+++ b/usr.bin/localedef/charmap.c
@@ -236,7 +236,7 @@
 	const charmap_t *c1 = n1;
 	const charmap_t *c2 = n2;
 
-	return ((c1->wc < c2->wc) ? -1 : (c1->wc > c2->wc) ? 1 : 0);
+	return (wchar_cmp(c1->wc, c2->wc));
 }
 
 void
diff --git a/usr.bin/localedef/collate.c b/usr.bin/localedef/collate.c
--- a/usr.bin/localedef/collate.c
+++ b/usr.bin/localedef/collate.c
@@ -422,7 +422,7 @@
 	wchar_t	k1 = ((const collchar_t *)n1)->wc;
 	wchar_t	k2 = ((const collchar_t *)n2)->wc;
 
-	return (k1 < k2 ? -1 : k1 > k2 ? 1 : 0);
+	return (wchar_cmp(k1, k2));
 }
 
 RB_GENERATE_STATIC(collchars, collchar, entry, collchar_compare);
diff --git a/usr.bin/localedef/ctype.c b/usr.bin/localedef/ctype.c
--- a/usr.bin/localedef/ctype.c
+++ b/usr.bin/localedef/ctype.c
@@ -93,7 +93,7 @@
 	const ctype_node_t *c1 = n1;
 	const ctype_node_t *c2 = n2;
 
-	return (c1->wc < c2->wc ? -1 : c1->wc > c2->wc ? 1 : 0);
+	return (wchar_cmp(c1->wc, c2->wc));
 }
 
 void
diff --git a/usr.bin/localedef/localedef.h b/usr.bin/localedef/localedef.h
--- a/usr.bin/localedef/localedef.h
+++ b/usr.bin/localedef/localedef.h
@@ -38,6 +38,7 @@
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <wchar.h>
 
 extern int com_char;
 extern int esc_char;
@@ -173,5 +174,19 @@
 const char *get_wide_encoding(void);
 int max_wide(void);
 
+/*
+ * A helper function to compare wide characters when sorting.  Forcibly cast to
+ * an unsigned type to help ensure that output is consistent no matter the
+ * signedness of wchar_t.
+ */
+static inline int
+wchar_cmp(const wchar_t a, const wchar_t b)
+{
+	return ((uint32_t)a < (uint32_t)b ? -1 :
+	    ((uint32_t)a > (uint32_t)b ? 1 : 0));
+}
+_Static_assert(sizeof(wchar_t) == sizeof(uint32_t),
+    "wchar_t must be 32 bits wide");
+
 //#define	_(x)	gettext(x)
 #define	INTERR	fprintf(stderr,"internal fault (%s:%d)\n", __FILE__, __LINE__)