diff --git a/regress/Makefile b/regress/Makefile
index a7b693c..195cb0d 100644
--- a/regress/Makefile
+++ b/regress/Makefile
@@ -33,7 +33,7 @@ testdata: fill-file
 	./sha testdata/bigfile testdata/bigfile.sha
 	printf "# hello world\n" > testdata/index.gmi
 	./sha testdata/index.gmi testdata/index.gmi.sha
-	cp hello slow err invalid testdata/
+	cp hello slow err invalid serve-bigfile testdata/
 	mkdir testdata/dir
 	cp testdata/index.gmi testdata/dir/foo.gmi
 
diff --git a/regress/runtime b/regress/runtime
index 6e62029..6456746 100755
--- a/regress/runtime
+++ b/regress/runtime
@@ -171,6 +171,13 @@ echo OK GET /err with cgi
 eq "$(raw /invalid | wc -c | xargs)" 2048		"Unexpected body for /invalid"
 echo OK GET /invalid with cgi
 
+# try a big file
+eq "$(head /serve-bigfile)"	"20 application/octet-stream" "Unexpected head for /serve-bigfile"
+get /bigfile > bigfile
+./sha bigfile bigfile.sha
+eq "$(cat bigfile.sha)"	"$(cat testdata/bigfile.sha)" "Unexpected sha for /serve-bigfile"
+echo OK GET /serve-bigfile with cgi
+
 check "should be running"
 quit
 
diff --git a/regress/serve-bigfile b/regress/serve-bigfile
new file mode 100644
index 0000000..56fb488
--- /dev/null
+++ b/regress/serve-bigfile
@@ -0,0 +1,5 @@
+#!/bin/sh
+
+printf "20 application/octet-stream\r\n"
+
+exec cat bigfile