diff --git a/readtags.c b/readtags.c
index 662cf9be..acf9170c 100644
--- a/readtags.c
+++ b/readtags.c
@@ -9,6 +9,15 @@
 /*
 *   INCLUDE FILES
 */
+#ifdef HAVE_CTAGS_INLINE_H
+/* the build script of ctags can insert thee macro
+   definition for READTAGS_INLINE. */
+#include "inline.h"
+#else
+/* Makefile generated by configure defines inline. */
+#define READTAGS_INLINE static inline
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <ctype.h>
@@ -151,8 +160,8 @@ static int xdigitValue (unsigned char digit)
  * Reads the first character from the string, possibly un-escaping it, and
  * advances *s to the start of the next character.
  */
-inline
-static int readTagCharacter (const char **const s)
+READTAGS_INLINE
+int readTagCharacter (const char **const s)
 {
 	const unsigned char *p = (const unsigned char *) *s;
 	int c = *p;