diff --git a/Makefile.am b/Makefile.am
index 6f86525..8728ff0 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -51,14 +51,8 @@ libjson_c_la_SOURCES = \
 	json_visit.c \
 	linkhash.c \
 	printbuf.c \
-	random_seed.c
-
-if ENABLE_STRERROR_OVERRIDE
-libjson_cinclude_HEADERS+= \
-	strerror_override.h
-libjson_c_la_SOURCES+= \
+	random_seed.c \
 	strerror_override.c
-endif
 
 distclean-local:
 	-rm -rf $(testsubdir)
diff --git a/configure.ac b/configure.ac
index 7af60bf..bbaacf5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -23,22 +23,6 @@ else
   AC_MSG_RESULT([RDRAND Hardware RNG Hash Seed disabled. Use --enable-rdrand to enable])
 fi
 
-AC_ARG_ENABLE(strerror-override,
- AS_HELP_STRING([--enable-strerror-override],
-   [Override strerror() function with internal version.]),
-[if test x$enableval = xyes; then
-  enable_strerror_override=yes
-  AC_DEFINE(ENABLE_STRERROR_OVERRIDE, 1, [Override strerror() with internal version])
-fi])
-
-AM_CONDITIONAL([ENABLE_STRERROR_OVERRIDE], [test "x$enable_strerror_override" = "xyes"])
-
-if test "x$enable_strerror_override" = "xyes"; then
-  AC_MSG_RESULT([Overriding `strerror()` function with internal version])
-else
-  AC_MSG_RESULT([Using libc's `strerror()` function])
-fi
-
 # enable silent build by default
 m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])])
 
diff --git a/strerror_override.c b/strerror_override.c
index 6cad0c0..ccabe97 100644
--- a/strerror_override.c
+++ b/strerror_override.c
@@ -1,3 +1,4 @@
+#define STERROR_OVERRIDE_IMPL 1
 #include "strerror_override.h"
 
 /*
@@ -52,6 +53,9 @@ static struct {
 	{ 0, (char *)0 }
 };
 
+// Enabled during tests
+int _json_c_strerror_enable = 0;
+
 #define PREFIX "ERRNO="
 static char errno_buf[128] = PREFIX;
 char *_json_c_strerror(int errno_in)
@@ -60,6 +64,9 @@ char *_json_c_strerror(int errno_in)
 	char digbuf[20];
 	int ii, jj;
 
+	if (!_json_c_strerror_enable)
+		return strerror(errno_in);
+
 	// Avoid standard functions, so we don't need to include any
 	// headers, or guess at signatures.
 
diff --git a/strerror_override.h b/strerror_override.h
index 96e6bc6..48b29b3 100644
--- a/strerror_override.h
+++ b/strerror_override.h
@@ -1,12 +1,13 @@
-#ifndef __STRERROR_OVERRIDE_H__
-#define __STRERROR_OVERRIDE_H__
+#ifndef _json_strerror_override_h_
+#define _json_strerror_override_h_
 
 #include "config.h"
 #include <errno.h>
 
-#if ENABLE_STRERROR_OVERRIDE
 char *_json_c_strerror(int errno_in);
+
+#ifndef STRERROR_OVERRIDE_IMPL
 #define strerror	_json_c_strerror
 #endif
 
-#endif /* __STRERROR_OVERRIDE_H__ */ 
+#endif /* _json_strerror_override_h_ */ 
diff --git a/tests/test_json_pointer.c b/tests/test_json_pointer.c
index cc96ab9..97566e2 100644
--- a/tests/test_json_pointer.c
+++ b/tests/test_json_pointer.c
@@ -1,4 +1,5 @@
 #include "strerror_override.h"
+#include "strerror_override_private.h"
 #include <assert.h>
 #include <stdio.h>
 #include <string.h>
@@ -280,6 +281,8 @@ static void test_wrong_inputs_set()
 
 int main(int argc, char **argv)
 {
+	_json_c_strerror_enable = 1;
+
 	test_example_get();
 	test_recursion_get();
 	test_wrong_inputs_get();
diff --git a/tests/test_util_file.c b/tests/test_util_file.c
index b4918be..5a8a8a0 100644
--- a/tests/test_util_file.c
+++ b/tests/test_util_file.c
@@ -1,4 +1,5 @@
 #include "strerror_override.h"
+#include "strerror_override_private.h"
 #include <stdio.h>
 #include <stdlib.h>
 #include <stddef.h>
@@ -114,6 +115,8 @@ int main(int argc, char **argv)
 //	json_object_to_file(file, obj);
 //	json_object_to_file_ext(file, obj, flags);
 
+	_json_c_strerror_enable = 1;
+
 	const char *testdir;
 	if (argc < 2)
 	{