diff --git a/lib/message/mu-message.cc b/lib/message/mu-message.cc
index d398d599..b2581b07 100644
--- a/lib/message/mu-message.cc
+++ b/lib/message/mu-message.cc
@@ -591,7 +591,7 @@ process_message(const MimeMessage& mime_msg, const std::string& path,
 	if (info.mailing_list)
 		info.flags |= Flags::MailingList;
 
-#ifdef HAVE_CLD2
+#if HAVE_CLD2
 	/* language detection requires the cld2 lib */
 	if (info.body_txt) { /* attempt to get the body-language */
 		if (const auto lang{detect_language(info.body_txt.value())}; lang) {
diff --git a/lib/tests/test-mu-store-query.cc b/lib/tests/test-mu-store-query.cc
index 6bff871e..54b0ad73 100644
--- a/lib/tests/test-mu-store-query.cc
+++ b/lib/tests/test-mu-store-query.cc
@@ -148,7 +148,7 @@ I said: "Aujourd'hui!"
 			"to:sqlite-dev@sqlite.org",
 			"list:sqlite-dev.sqlite.org",
 			"aujourd'hui",
-#ifdef HAVE_CLD2
+#if HAVE_CLD2
 			"lang:en",
 #endif /*HAVE_CLD2*/
 		}) {
diff --git a/lib/utils/mu-lang-detector.cc b/lib/utils/mu-lang-detector.cc
index 75af37eb..9304c9dc 100644
--- a/lib/utils/mu-lang-detector.cc
+++ b/lib/utils/mu-lang-detector.cc
@@ -21,7 +21,7 @@
 
 using namespace Mu;
 
-#ifndef HAVE_CLD2
+#if HAVE_CLD2
 // Dummy implementation
 Option<Language> Mu::detect_language(const std::string& txt) { return Nothing; }
 #else
diff --git a/mu/tests/test-mu-query.cc b/mu/tests/test-mu-query.cc
index 9de70f4c..ac336b98 100644
--- a/mu/tests/test-mu-query.cc
+++ b/mu/tests/test-mu-query.cc
@@ -139,7 +139,7 @@ test_mu_query_01(void)
 	    { "", 19 },
 	    {"msgid:abcd$efgh@example.com", 1},
 	    {"i:abcd$efgh@example.com", 1},
-#ifdef HAVE_CLD2
+#if HAVE_CLD2
 {	    "lang:en",  14},
 #endif /*HAVE_CLD2*/
 	};