diff --git a/src/regexp.h b/src/regexp.h
new file mode 100644
index 0000000..15611ed
--- /dev/null
+++ b/src/regexp.h
@@ -0,0 +1,80 @@
+/* vi:set ts=8 sts=4 sw=4:
+ *
+ * NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE
+ *
+ * This is NOT the original regular expression code as written by Henry
+ * Spencer.  This code has been modified specifically for use with Vim, and
+ * should not be used apart from compiling Vim.  If you want a good regular
+ * expression library, get the original code.
+ *
+ * NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE
+ */
+
+#ifndef _REGEXP_H
+#define _REGEXP_H
+
+/*
+ * The number of sub-matches is limited to 10.
+ * The first one (index 0) is the whole match, referenced with "\0".
+ * The second one (index 1) is the first sub-match, referenced with "\1".
+ * This goes up to the tenth (index 9), referenced with "\9".
+ */
+#define NSUBEXP  10
+
+/*
+ * Structure returned by vim_regcomp() to pass on to vim_regexec().
+ * These fields are only to be used in regexp.c!
+ * See regep.c for an explanation.
+ */
+typedef struct
+{
+    int			regstart;
+    char_u		reganch;
+    char_u		*regmust;
+    int			regmlen;
+    unsigned		regflags;
+    char_u		reghasz;
+    char_u		program[1];		/* actually longer.. */
+} regprog_T;
+
+/*
+ * Structure to be used for single-line matching.
+ * Sub-match "no" starts at "startp[no]" and ends just before "endp[no]".
+ * When there is no match, the pointer is NULL.
+ */
+typedef struct
+{
+    regprog_T		*regprog;
+    char_u		*startp[NSUBEXP];
+    char_u		*endp[NSUBEXP];
+    int			rm_ic;
+} regmatch_T;
+
+/*
+ * Structure to be used for multi-line matching.
+ * Sub-match "no" starts in line "startpos[no].lnum" column "startpos[no].col"
+ * and ends in line "endpos[no].lnum" just before column "endpos[no].col".
+ * The line numbers are relative to the first line, thus startpos[0].lnum is
+ * always 0.
+ * When there is no match, the line number is -1.
+ */
+typedef struct
+{
+    regprog_T		*regprog;
+    lpos_T		startpos[NSUBEXP];
+    lpos_T		endpos[NSUBEXP];
+    int			rmm_ic;
+} regmmatch_T;
+
+/*
+ * Structure used to store external references: "\z\(\)" to "\z\1".
+ * Use a reference count to avoid the need to copy this around.  When it goes
+ * from 1 to zero the matches need to be freed.
+ */
+typedef struct
+{
+    short		refcnt;
+    char_u		*matches[NSUBEXP];
+} reg_extmatch_T;
+
+#endif	/* _REGEXP_H */