diff --git a/src/proto/linematch.pro b/src/proto/linematch.pro
new file mode 100644
index 0000000..56d0037
--- /dev/null
+++ b/src/proto/linematch.pro
@@ -0,0 +1,3 @@
+/* linematch.c */
+size_t linematch_nbuffers(const mmfile_t **diff_blk, const int *diff_len, const size_t ndiffs, int **decisions, int iwhite);
+/* vim: set ft=c : */