diff --git cctools/include/foreign/i386/_types.h cctools/include/foreign/i386/_types.h
index 601b196..8bffd6f 100644
--- cctools/include/foreign/i386/_types.h
+++ cctools/include/foreign/i386/_types.h
@@ -33,6 +33,15 @@
  * flotaing point and other arithmetic types, as needed, later.
  */
 
+/*
+ * Silence old glibc -Wtypedef-redefinition warnings.
+ * https://github.com/tpoechtrager/cctools-port/pull/8
+ */
+#ifdef __clang__
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wtypedef-redefinition"
+#endif
+
 #ifdef __GNUC__
 typedef __signed char		__int8_t;
 #else	/* !__GNUC__ */
@@ -121,4 +130,8 @@ typedef __uint32_t		__darwin_socklen_t;	/* socklen_t (duh) */
 typedef long			__darwin_ssize_t;	/* byte count or error */
 typedef long			__darwin_time_t;	/* time() */
 
+#ifdef __clang__
+#pragma clang diagnostic pop
+#endif
+
 #endif	/* _BSD_I386__TYPES_H_ */
diff --git cctools/ld64/src/3rd/strlcat.c cctools/ld64/src/3rd/strlcat.c
index ef1a10a..faf09e3 100644
--- cctools/ld64/src/3rd/strlcat.c
+++ cctools/ld64/src/3rd/strlcat.c
@@ -23,6 +23,14 @@
 
 #ifndef __APPLE__
 
+/*
+ * Otherwise string.h may hide strnlen().
+ * https://github.com/tpoechtrager/cctools-port/pull/8
+ */
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
 #include <string.h>
 
 size_t
diff --git cctools/otool/ofile_print.c cctools/otool/ofile_print.c
index 3eb6506..4e9493a 100644
--- cctools/otool/ofile_print.c
+++ cctools/otool/ofile_print.c
@@ -201,6 +201,14 @@
 #define __dr6 dr6
 #define __dr7 dr7
 
+/*
+ * Otherwise string.h may hide strnlen().
+ * https://github.com/tpoechtrager/cctools-port/pull/8
+ */
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
 #include <stdlib.h>
 #include <stddef.h>
 #include <string.h>