diff --git a/builtin/commit.c b/builtin/commit.c
index 80a618fe13..537e228c3a 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -669,52 +669,6 @@ static void adjust_comment_line_char(const struct strbuf *sb)
 	comment_line_char = *p;
 }
 
-/*
- * Inspect sb and determine the true "end" of the log message, in
- * order to find where to put a new Signed-off-by: line.  Ignored are
- * trailing comment lines and blank lines, and also the traditional
- * "Conflicts:" block that is not commented out, so that we can use
- * "git commit -s --amend" on an existing commit that forgot to remove
- * it.
- *
- * Returns the number of bytes from the tail to ignore, to be fed as
- * the second parameter to append_signoff().
- */
-static int ignore_non_trailer(struct strbuf *sb)
-{
-	int boc = 0;
-	int bol = 0;
-	int in_old_conflicts_block = 0;
-
-	while (bol < sb->len) {
-		char *next_line;
-
-		if (!(next_line = memchr(sb->buf + bol, '\n', sb->len - bol)))
-			next_line = sb->buf + sb->len;
-		else
-			next_line++;
-
-		if (sb->buf[bol] == comment_line_char || sb->buf[bol] == '\n') {
-			/* is this the first of the run of comments? */
-			if (!boc)
-				boc = bol;
-			/* otherwise, it is just continuing */
-		} else if (starts_with(sb->buf + bol, "Conflicts:\n")) {
-			in_old_conflicts_block = 1;
-			if (!boc)
-				boc = bol;
-		} else if (in_old_conflicts_block && sb->buf[bol] == '\t') {
-			; /* a pathname in the conflicts block */
-		} else if (boc) {
-			/* the previous was not trailing comment */
-			boc = 0;
-			in_old_conflicts_block = 0;
-		}
-		bol = next_line - sb->buf;
-	}
-	return boc ? sb->len - boc : 0;
-}
-
 static int prepare_to_commit(const char *index_file, const char *prefix,
 			     struct commit *current_head,
 			     struct wt_status *s,
diff --git a/commit.c b/commit.c
index ae7f2b10f4..07d2290d0d 100644
--- a/commit.c
+++ b/commit.c
@@ -1660,3 +1660,49 @@ void print_commit_list(struct commit_list *list,
 		printf(format, sha1_to_hex(list->item->object.sha1));
 	}
 }
+
+/*
+ * Inspect sb and determine the true "end" of the log message, in
+ * order to find where to put a new Signed-off-by: line.  Ignored are
+ * trailing comment lines and blank lines, and also the traditional
+ * "Conflicts:" block that is not commented out, so that we can use
+ * "git commit -s --amend" on an existing commit that forgot to remove
+ * it.
+ *
+ * Returns the number of bytes from the tail to ignore, to be fed as
+ * the second parameter to append_signoff().
+ */
+int ignore_non_trailer(struct strbuf *sb)
+{
+	int boc = 0;
+	int bol = 0;
+	int in_old_conflicts_block = 0;
+
+	while (bol < sb->len) {
+		char *next_line;
+
+		if (!(next_line = memchr(sb->buf + bol, '\n', sb->len - bol)))
+			next_line = sb->buf + sb->len;
+		else
+			next_line++;
+
+		if (sb->buf[bol] == comment_line_char || sb->buf[bol] == '\n') {
+			/* is this the first of the run of comments? */
+			if (!boc)
+				boc = bol;
+			/* otherwise, it is just continuing */
+		} else if (starts_with(sb->buf + bol, "Conflicts:\n")) {
+			in_old_conflicts_block = 1;
+			if (!boc)
+				boc = bol;
+		} else if (in_old_conflicts_block && sb->buf[bol] == '\t') {
+			; /* a pathname in the conflicts block */
+		} else if (boc) {
+			/* the previous was not trailing comment */
+			boc = 0;
+			in_old_conflicts_block = 0;
+		}
+		bol = next_line - sb->buf;
+	}
+	return boc ? sb->len - boc : 0;
+}
diff --git a/commit.h b/commit.h
index a401ddfbc4..f87b392506 100644
--- a/commit.h
+++ b/commit.h
@@ -326,6 +326,9 @@ extern struct commit_extra_header *read_commit_extra_headers(struct commit *, co
 
 extern void free_commit_extra_headers(struct commit_extra_header *extra);
 
+/* Find the end of the log message, the right place for a new trailer. */
+extern int ignore_non_trailer(struct strbuf *sb);
+
 typedef void (*each_mergetag_fn)(struct commit *commit, struct commit_extra_header *extra,
 				 void *cb_data);