--- a/ustr-conf.h.in	2007-10-22 08:00:55.000000000 +0200
+++ b/ustr-conf.h.in	2015-09-10 12:24:34.998796842 +0200
@@ -4,13 +4,23 @@
 /* this is the custom version for the library itself, for everyone else
  * ustr-import generates one depending on the options. */
 
+/* Ustr relies on GCC's traditional handling of inline functions, not
+ * the version that was actually standardized in C99. GCC-compatible
+ * compilers define __GNUC_STDC_INLINE__ when using the standard
+ * behavior. When this is set we must restore the old inline behavior:
+ */
+#if defined(__GNUC__) \
+ && defined(__GNUC_STDC_INLINE__)
+#  define inline inline __attribute__ ((gnu_inline))
+#endif
+
 /* The default is now to link against libc. */
 #ifndef USTR_CONF_INCLUDE_CODEONLY_HEADERS
 #define USTR_CONF_INCLUDE_CODEONLY_HEADERS 0
 #endif
 
 /* We can't: if defined(__GLIBC__) && (!defined(_GNU_SOURCE) || !_GNU_SOURCE)
- *  because by the time we've included a libc header it's too late. */ 
+ *  because by the time we've included a libc header it's too late. */
 #ifndef _GNU_SOURCE
 #define _GNU_SOURCE 1
 #endif