diff --git a/test.sh b/test.sh
index 3cef9ad..2dd244f 100755
--- a/test.sh
+++ b/test.sh
@@ -4,6 +4,9 @@ set -eux
 
 cd $(dirname $0)
 
+# Make sure that the testsuite submodule is checked out.
+git submodule update --init wasmi/tests/spec/testsuite
+
 time cargo test
 
 cd -