diff --git a/print_sha1.h b/print_sha1.h
index 1f85895..d0c18b3 100644
--- a/print_sha1.h
+++ b/print_sha1.h
@@ -32,15 +32,15 @@
     return result;
 }
 
-static std::string print_sha1(const uint8_t sha1[SHA_DIGEST_LENGTH]) {
+[[maybe_unused]] static std::string print_sha1(const uint8_t sha1[SHA_DIGEST_LENGTH]) {
     return print_sha1(sha1, SHA_DIGEST_LENGTH);
 }
 
-static std::string short_sha1(const uint8_t sha1[SHA_DIGEST_LENGTH]) {
+[[maybe_unused]] static std::string short_sha1(const uint8_t sha1[SHA_DIGEST_LENGTH]) {
     return print_sha1(sha1, 4);
 }
 
-static std::string print_hex(const uint8_t* bytes, size_t len) {
+[[maybe_unused]] static std::string print_hex(const uint8_t* bytes, size_t len) {
     return print_sha1(bytes, len);
 }