diff --git a/lib/libarchive/test/main.c b/lib/libarchive/test/main.c
index ffe81cf30a51..a7289ec236ef 100644
--- a/lib/libarchive/test/main.c
+++ b/lib/libarchive/test/main.c
@@ -34,11 +34,8 @@
  */
 #define PROGRAM "LIBARCHIVE"
 
-/*
- * Various utility routines useful for test programs.
- * Each test program is linked against this file.
- */
 #include <errno.h>
+#include <locale.h>
 #include <stdarg.h>
 #include <time.h>
 
@@ -226,20 +223,21 @@ failure(const char *fmt, ...)
 }
 
 /* Generic assert() just displays the failed condition. */
-void
+int
 test_assert(const char *file, int line, int value, const char *condition, void *extra)
 {
 	++assertions;
 	if (value) {
 		msg[0] = '\0';
-		return;
+		return (value);
 	}
 	failures ++;
 	if (previous_failures(file, line))
-		return;
+		return (value);
 	fprintf(stderr, "%s:%d: Assertion failed\n", file, line);
 	fprintf(stderr, "   Condition: %s\n", condition);
 	report_failure(extra);
+	return (value);
 }
 
 /* assertEqualInt() displays the values of the two integers. */
@@ -553,6 +551,8 @@ static int test_run(int i, const char *tmpdir)
 		    tests[i].name);
 		exit(1);
 	}
+	/* Explicitly reset the locale before each test. */
+	setlocale(LC_ALL, "C");
 	/* Run the actual test. */
 	(*tests[i].func)();
 	/* Summarize the results of this test. */
diff --git a/lib/libarchive/test/test.h b/lib/libarchive/test/test.h
index 3ec41eba7236..07de016f3219 100644
--- a/lib/libarchive/test/test.h
+++ b/lib/libarchive/test/test.h
@@ -31,8 +31,9 @@
  * The goal of this file (and the matching test.c) is to
  * simplify the very repetitive test-*.c test programs.
  */
-
+#ifndef _FILE_OFFSET_BITS
 #define _FILE_OFFSET_BITS 64
+#endif
 
 #include <errno.h>
 #include <fcntl.h>
@@ -40,7 +41,9 @@
 #include <stdlib.h>
 #include <string.h>
 #include <sys/stat.h>
+#ifndef _WIN32
 #include <unistd.h>
+#endif
 #include <wchar.h>
 
 #ifdef USE_DMALLOC
@@ -112,7 +115,7 @@
 void failure(const char *fmt, ...);
 void test_setup(const char *, int);
 void test_skipping(const char *fmt, ...);
-void test_assert(const char *, int, int, const char *, void *);
+int test_assert(const char *, int, int, const char *, void *);
 void test_assert_empty_file(const char *, ...);
 void test_assert_equal_file(const char *, const char *, ...);
 void test_assert_equal_int(const char *, int, int, const char *, int, const char *, void *);