diff --git a/filter.c b/filter.c
index 3702585..7983737 100644
--- a/filter.c
+++ b/filter.c
@@ -351,6 +351,8 @@ int cgit_open_filter(struct cgit_filter *filter, ...)
 {
 	int result;
 	va_list ap;
+	if (!filter)
+		return 0;
 	va_start(ap, filter);
 	result = filter->open(filter, ap);
 	va_end(ap);
@@ -359,6 +361,8 @@ int cgit_open_filter(struct cgit_filter *filter, ...)
 
 int cgit_close_filter(struct cgit_filter *filter)
 {
+	if (!filter)
+		return 0;
 	return filter->close(filter);
 }
 
diff --git a/ui-commit.c b/ui-commit.c
index aa1892f..5ac79c0 100644
--- a/ui-commit.c
+++ b/ui-commit.c
@@ -107,28 +107,22 @@ void cgit_print_commit(char *hex, const char *prefix)
 	}
 	html("</table>\n");
 	html("<div class='commit-subject'>");
-	if (ctx.repo->commit_filter)
-		cgit_open_filter(ctx.repo->commit_filter);
+	cgit_open_filter(ctx.repo->commit_filter);
 	html_txt(info->subject);
-	if (ctx.repo->commit_filter)
-		cgit_close_filter(ctx.repo->commit_filter);
+	cgit_close_filter(ctx.repo->commit_filter);
 	show_commit_decorations(commit);
 	html("</div>");
 	html("<div class='commit-msg'>");
-	if (ctx.repo->commit_filter)
-		cgit_open_filter(ctx.repo->commit_filter);
+	cgit_open_filter(ctx.repo->commit_filter);
 	html_txt(info->msg);
-	if (ctx.repo->commit_filter)
-		cgit_close_filter(ctx.repo->commit_filter);
+	cgit_close_filter(ctx.repo->commit_filter);
 	html("</div>");
 	if (notes.len != 0) {
 		html("<div class='notes-header'>Notes</div>");
 		html("<div class='notes'>");
-		if (ctx.repo->commit_filter)
-			cgit_open_filter(ctx.repo->commit_filter);
+		cgit_open_filter(ctx.repo->commit_filter);
 		html_txt(notes.buf);
-		if (ctx.repo->commit_filter)
-			cgit_close_filter(ctx.repo->commit_filter);
+		cgit_close_filter(ctx.repo->commit_filter);
 		html("</div>");
 		html("<div class='notes-footer'></div>");
 	}
diff --git a/ui-repolist.c b/ui-repolist.c
index 7b1fec3..f9cb21a 100644
--- a/ui-repolist.c
+++ b/ui-repolist.c
@@ -333,9 +333,7 @@ void cgit_print_site_readme()
 {
 	if (!ctx.cfg.root_readme)
 		return;
-	if (ctx.cfg.about_filter)
-		cgit_open_filter(ctx.cfg.about_filter, ctx.cfg.root_readme);
+	cgit_open_filter(ctx.cfg.about_filter, ctx.cfg.root_readme);
 	html_include(ctx.cfg.root_readme);
-	if (ctx.cfg.about_filter)
-		cgit_close_filter(ctx.cfg.about_filter);
+	cgit_close_filter(ctx.cfg.about_filter);
 }
diff --git a/ui-summary.c b/ui-summary.c
index 725f3ab..ddd8f1b 100644
--- a/ui-summary.c
+++ b/ui-summary.c
@@ -151,16 +151,12 @@ void cgit_print_repo_readme(char *path)
 	 * filesystem, while applying the about-filter.
 	 */
 	html("<div id='summary'>");
-	if (ctx.repo->about_filter)
-		cgit_open_filter(ctx.repo->about_filter, filename);
-
+	cgit_open_filter(ctx.repo->about_filter, filename);
 	if (ref)
 		cgit_print_file(filename, ref, 1);
 	else
 		html_include(filename);
-
-	if (ctx.repo->about_filter)
-		cgit_close_filter(ctx.repo->about_filter);
+	cgit_close_filter(ctx.repo->about_filter);
 
 	html("</div>");
 	if (free_filename)