diff --git a/sys/regexp.h b/sys/regexp.h
new file mode 100644
index 0000000..7c0f10c
--- /dev/null
+++ b/sys/regexp.h
@@ -0,0 +1,42 @@
+#ifndef LPC_REGEXP_H_
+#define LPC_REGEXP_H_ 1
+
+/* Definitions of regexp option values */
+
+/* Not really an RE option, but used in conjunction with some RE functions: */
+
+#define RE_GLOBAL          0x0001  /* Apply RE globally (if possible) */
+
+/* Options supported by the old regexp package: */
+
+#define RE_EXCOMPATIBLE    0x0002  /* RE is compatible with ex */
+
+/* Options supported by the PCRE regexp package: */
+
+#define RE_CASELESS        0x0004
+#define RE_MULTILINE       0x0008
+#define RE_DOTALL          0x0010
+#define RE_EXTENDED        0x0020
+#define RE_ANCHORED        0x0040
+#define RE_DOLLAR_ENDONLY  0x0080
+#define RE_NOTBOL          0x0100
+#define RE_NOTEOL          0x0200
+#define RE_UNGREEDY        0x0400
+#define RE_NOTEMPTY        0x0800
+
+/* Options specific for regmatch(): */
+
+#define RE_MATCH_SUBS      0x1000  /* Return matched subexpressions */
+
+/* Options specific for regexplode(): */
+
+#define RE_OMIT_DELIM      0x1000  /* Omit the delimiters */
+
+/* Regexp package selection options: */
+
+#define RE_TRADITIONAL     0x04000000
+#define RE_PCRE            0x02000000
+
+#define RE_PACKAGE_MASK    (RE_TRADITIONAL | RE_PCRE)
+
+#endif /* LPC_REGEXP_H_ */