diff --git a/libcxx/include/__support/openbsd/xlocale.h b/libcxx/include/__support/openbsd/xlocale.h
--- a/libcxx/include/__support/openbsd/xlocale.h
+++ b/libcxx/include/__support/openbsd/xlocale.h
@@ -16,4 +16,24 @@
 #include <ctype.h>
 #include <cwctype>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+static inline long strtol_l(const char *nptr, char **endptr, int base,
+                            locale_t) {
+  return strtol(nptr, endptr, base);
+}
+
+static inline unsigned long strtoul_l(const char *nptr, char **endptr,
+                                      int base, locale_t) {
+  return strtoul(nptr, endptr, base);
+}
+
+
+#ifdef __cplusplus
+}
+#endif
+
 #endif