diff --git a/test/T670-duplicate-mid.sh b/test/T670-duplicate-mid.sh
new file mode 100755
index 00000000..ced28a21
--- /dev/null
+++ b/test/T670-duplicate-mid.sh
@@ -0,0 +1,28 @@
+#!/usr/bin/env bash
+test_description="duplicate message ids"
+. ./test-lib.sh || exit 1
+
+add_message '[id]="duplicate"' '[subject]="message 1" [filename]=copy1'
+add_message '[id]="duplicate"' '[subject]="message 2" [filename]=copy2'
+
+test_begin_subtest 'Search for second subject'
+test_subtest_known_broken
+cat <<EOF >EXPECTED
+MAIL_DIR/copy1
+MAIL_DIR/copy2
+EOF
+notmuch search --output=files subject:'"message 2"' | notmuch_dir_sanitize > OUTPUT
+test_expect_equal_file EXPECTED OUTPUT
+
+add_message '[id]="duplicate"' '[body]="sekrit" [filename]=copy3'
+test_begin_subtest 'search for body in duplicate file'
+test_subtest_known_broken
+cat <<EOF >EXPECTED
+MAIL_DIR/copy1
+MAIL_DIR/copy2
+MAIL_DIR/copy3
+EOF
+notmuch search --output=files "sekrit" | notmuch_dir_sanitize > OUTPUT
+test_expect_equal_file EXPECTED OUTPUT
+
+test_done