diff --git a/libc/src/unistd/getopt.h b/libc/src/unistd/getopt.h
--- a/libc/src/unistd/getopt.h
+++ b/libc/src/unistd/getopt.h
@@ -15,7 +15,7 @@
 namespace __llvm_libc {
 
 namespace impl {
-void set_getopt_state(char **, int *, int *, unsigned *, int, FILE *);
+void set_getopt_state(char **, int *, int *, unsigned *, int *, FILE *);
 }
 
 int getopt(int argc, char *const argv[], const char *optstring);
diff --git a/libc/src/unistd/getopt.cpp b/libc/src/unistd/getopt.cpp
--- a/libc/src/unistd/getopt.cpp
+++ b/libc/src/unistd/getopt.cpp
@@ -22,7 +22,6 @@
 namespace __llvm_libc {
 
 template <typename T> struct RefWrapper {
-  RefWrapper(T *ptr) : ptr(ptr) {}
   RefWrapper &operator=(const RefWrapper &) = default;
   operator T &() { return *ptr; }
   T &get() { return *ptr; }
@@ -35,7 +34,7 @@
   RefWrapper<int> optopt;
   RefWrapper<unsigned> optpos;
 
-  int opterr;
+  RefWrapper<int> opterr;
 
   FILE *errstream;
 
@@ -43,7 +42,9 @@
 
   template <typename... Ts> void report_error(const char *fmt, Ts... ts) {
     if (opterr)
-      __llvm_libc::fprintf(errstream, fmt, ts...);
+      __llvm_libc::fprintf(
+          errstream ? errstream : reinterpret_cast<FILE *>(__llvm_libc::stderr),
+          fmt, ts...);
   }
 };
 
@@ -171,25 +172,21 @@
 namespace impl {
 
 extern "C" {
-
 char *optarg = nullptr;
 int optind = 1;
 int optopt = 0;
 int opterr = 0;
-
 }
 
 static unsigned optpos;
 
-static GetoptContext ctx{
-    &impl::optarg, &impl::optind,
-    &impl::optopt, &optpos,
-    impl::opterr,  reinterpret_cast<FILE *>(__llvm_libc::stderr)};
+static GetoptContext ctx{&impl::optarg, &impl::optind, &impl::optopt,
+                         &optpos,       &impl::opterr, /*errstream=*/nullptr};
 
 #ifndef LIBC_COPT_PUBLIC_PACKAGING
 // This is used exclusively in tests.
 void set_getopt_state(char **optarg, int *optind, int *optopt, unsigned *optpos,
-                      int opterr, FILE *errstream) {
+                      int *opterr, FILE *errstream) {
   ctx = {optarg, optind, optopt, optpos, opterr, errstream};
 }
 #endif
diff --git a/libc/test/src/unistd/getopt_test.cpp b/libc/test/src/unistd/getopt_test.cpp
--- a/libc/test/src/unistd/getopt_test.cpp
+++ b/libc/test/src/unistd/getopt_test.cpp
@@ -31,7 +31,7 @@
 void set_state(FILE *errstream) {
   __llvm_libc::impl::set_getopt_state(
       &test_globals::optarg, &test_globals::optind, &test_globals::optopt,
-      &test_globals::optpos, test_globals::opterr, errstream);
+      &test_globals::optpos, &test_globals::opterr, errstream);
 }
 
 // TODO: <stdio> could be either llvm-libc's or the system libc's. The former