diff --git a/src/test_libexim-encrypt-dlfunc-decrypt-secretbox.sh b/src/test_libexim-encrypt-dlfunc-decrypt-secretbox.sh
index c67310f..b9d915f 100755
--- a/src/test_libexim-encrypt-dlfunc-decrypt-secretbox.sh
+++ b/src/test_libexim-encrypt-dlfunc-decrypt-secretbox.sh
@@ -10,8 +10,7 @@ TEST_CLEARTEXT='This is my cleartext'
 TEST_CIPHERTEXT01='RCHI+VukmWIsVE3eixbWIAtPPBW63nmV1ITpSBEDYXC9Y5QMBd1zmGLLhE+S9yg0sHfOF/1+wmfF7YXv'
 TEST_CIPHERTEXT02='sEG09WnEKIN2nyJYGNNVo14o7wV6X9HQxW+zxAxMLX9jVdashdaoHqLXQGM8lzpJhG6629lccjzAfrq8'
 
-LIBEXIM_PASSWORD="${TEST_PASSWORD}"
-DECRYPTED01="$(src/libexim-encrypt-dlfunc-decrypt-secretbox ${TEST_CIPHERTEXT01})"
+DECRYPTED01="$(LIBEXIM_PASSWORD="${TEST_PASSWORD}" src/libexim-encrypt-dlfunc-decrypt-secretbox ${TEST_CIPHERTEXT01})"
 
 if [ "${DECRYPTED01}" == "${TEST_CLEARTEXT}" ] ; then
   echo "decryption with password from environment successful"