diff --git a/libc/include/bits/fortify/stdlib.h b/libc/include/bits/fortify/stdlib.h
index 0bb3d0d..623be58 100644
--- a/libc/include/bits/fortify/stdlib.h
+++ b/libc/include/bits/fortify/stdlib.h
@@ -36,10 +36,11 @@
 #define __PATH_MAX 4096
 
 char* realpath(const char* path, char* resolved)
+        __clang_error_if(!path, "'realpath': NULL path is never correct; flipped arguments?")
         __clang_error_if(__bos_unevaluated_lt(__bos(resolved), __PATH_MAX),
                          "'realpath' output parameter must be NULL or a pointer to a buffer "
-                         "with >= PATH_MAX bytes")
-        __clang_error_if(!path, "'realpath': NULL path is never correct; flipped arguments?");
+                         "with >= PATH_MAX bytes");
+
 /* No need for a definition; the only issues we can catch are at compile-time. */
 
 #undef __PATH_MAX
diff --git a/libc/include/stdlib.h b/libc/include/stdlib.h
index d5b8619..b66e3c6 100644
--- a/libc/include/stdlib.h
+++ b/libc/include/stdlib.h
@@ -90,7 +90,7 @@
 long atol(const char* __s) __attribute_pure__;
 long long atoll(const char* __s) __attribute_pure__;
 
-char* realpath(const char* __path, char* __resolved);
+__wur char* realpath(const char* __path, char* __resolved);
 int system(const char* __command);
 
 void* bsearch(const void* __key, const void* __base, size_t __nmemb, size_t __size, int (*__comparator)(const void* __lhs, const void* __rhs));