diff --git a/.github/workflows/linux.yml b/.github/workflows/linux.yml
index 663c4dd0264..8bc2dc4f091 100644
--- a/.github/workflows/linux.yml
+++ b/.github/workflows/linux.yml
@@ -37,6 +37,7 @@ jobs:
           - fedora:42
           - fedora:43
           - fedora:44
+          - fedora:45
 
           - opensuse/leap:15.6
           - opensuse/leap:16.0
diff --git a/lib/base/tlsutility.cpp b/lib/base/tlsutility.cpp
index bf8a2076345..9ba840b43aa 100644
--- a/lib/base/tlsutility.cpp
+++ b/lib/base/tlsutility.cpp
@@ -403,7 +403,7 @@ void AddCRLToSSLContext(X509_STORE *x509_store, const String& crlPath)
 	X509_VERIFY_PARAM_free(param);
 }
 
-static String GetX509NameCN(X509_NAME *name)
+static String GetX509NameCN(X509NameConstPtr name)
 {
 	char errbuf[256];
 	char buffer[256];
@@ -598,8 +598,25 @@ int MakeX509CSR(
 		X509_REQ_set_version(req, 0);
 		X509_REQ_set_pubkey(req, key);
 
-		X509_NAME *name = X509_REQ_get_subject_name(req);
-		X509_NAME_add_entry_by_txt(name, "CN", MBSTRING_ASC, (unsigned char *)cn.CStr(), -1, -1, 0);
+		std::unique_ptr<X509_NAME, decltype(&X509_NAME_free)> name{X509_NAME_new(), &X509_NAME_free};
+		if (!name) {
+			unsigned long err = ERR_peek_error();
+			BOOST_THROW_EXCEPTION(openssl_error()
+				<< boost::errinfo_api_function("X509_NAME_new")
+				<< errinfo_openssl_error(err));
+		}
+
+		X509_NAME_add_entry_by_txt(name.get(), "CN", MBSTRING_ASC, (unsigned char *)cn.CStr(), -1, -1, 0);
+
+		if (!X509_REQ_set_subject_name(req, name.get())) {
+			unsigned long err = ERR_peek_error();
+			ERR_error_string_n(err, errbuf, sizeof errbuf);
+			Log(LogCritical, "SSL")
+				<< "Error while setting CSR subject name: " << err << ", \"" << errbuf << "\"";
+			BOOST_THROW_EXCEPTION(openssl_error()
+				<< boost::errinfo_api_function("X509_REQ_set_subject_name")
+				<< errinfo_openssl_error(err));
+		}
 
 		if (!ca) {
 			String san = "DNS:" + cn;
@@ -652,8 +669,8 @@ int MakeX509CSR(
 
 std::shared_ptr<X509> CreateCert(
 	EVP_PKEY* pubkey,
-	X509_NAME* subject,
-	X509_NAME* issuer,
+	X509NameConstPtr subject,
+	X509NameConstPtr issuer,
 	EVP_PKEY* cakey,
 	long validFrom,
 	long validFor,
@@ -746,7 +763,7 @@ String GetIcingaCADir()
 	return Configuration::DataDir + "/ca";
 }
 
-std::shared_ptr<X509> CreateCertIcingaCA(EVP_PKEY *pubkey, X509_NAME *subject, long validFrom, long validFor, bool ca)
+std::shared_ptr<X509> CreateCertIcingaCA(EVP_PKEY *pubkey, X509NameConstPtr subject, long validFrom, long validFor, bool ca)
 {
 	char errbuf[256];
 
diff --git a/lib/base/tlsutility.hpp b/lib/base/tlsutility.hpp
index 008fc90d69b..d39523c9a9b 100644
--- a/lib/base/tlsutility.hpp
+++ b/lib/base/tlsutility.hpp
@@ -39,6 +39,11 @@ const auto LEAF_VALID_FOR  = 60 * 60 * 24 * 397;
 const auto RENEW_THRESHOLD = 60 * 60 * 24 * 30;
 const auto RENEW_INTERVAL  = 60 * 60 * 24;
 
+// Tracks the constness of X509_NAME* across OpenSSL versions: on 1.x getters return X509_NAME* and
+// setters expect X509_NAME*; on 4.x both sides became const X509_NAME*. Using decltype on the getter
+// gives us the right type automatically, so we can accept getter results and pass to setters cast-free.
+using X509NameConstPtr = decltype(X509_get_subject_name(nullptr));
+
 void InitializeOpenSSL();
 
 String GetOpenSSLVersion();
@@ -66,8 +71,8 @@ int MakeX509CSR(
 );
 std::shared_ptr<X509> CreateCert(
 	EVP_PKEY* pubkey,
-	X509_NAME* subject,
-	X509_NAME* issuer,
+	X509NameConstPtr subject,
+	X509NameConstPtr issuer,
 	EVP_PKEY* cakey,
 	long validFrom,
 	long validFor,
@@ -83,7 +88,7 @@ inline String CertificateToString(const std::shared_ptr<X509>& cert)
 }
 
 std::shared_ptr<X509> StringToCertificate(const String& cert);
-std::shared_ptr<X509> CreateCertIcingaCA(EVP_PKEY *pubkey, X509_NAME *subject, long validFrom, long validFor, bool ca = false);
+std::shared_ptr<X509> CreateCertIcingaCA(EVP_PKEY *pubkey, X509NameConstPtr subject, long validFrom, long validFor, bool ca = false);
 std::shared_ptr<X509> CreateCertIcingaCA(const std::shared_ptr<X509>& cert, long validFrom = 0, long validFor = LEAF_VALID_FOR);
 bool IsCertUptodate(const std::shared_ptr<X509>& cert);
 bool IsCaUptodate(X509* cert);
diff --git a/lib/remote/pkiutility.cpp b/lib/remote/pkiutility.cpp
index c8c6b01174a..bd36b947854 100644
--- a/lib/remote/pkiutility.cpp
+++ b/lib/remote/pkiutility.cpp
@@ -345,10 +345,8 @@ String PkiUtility::GetCertificateInformation(const std::shared_ptr<X509>& cert)
 
 	pre = "\n Serial:              ";
 	BIO_write(out, pre.CStr(), pre.GetLength());
-	ASN1_INTEGER *asn1_serial = X509_get_serialNumber(cert.get());
-	for (int i = 0; i < asn1_serial->length; i++) {
-		BIO_printf(out, "%02x%c", asn1_serial->data[i], ((i + 1 == asn1_serial->length) ? '\n' : ':'));
-	}
+	i2a_ASN1_INTEGER(out, X509_get0_serialNumber(cert.get()));
+	BIO_write(out, "\n", 1);
 
 	pre = "\n Signature Algorithm: " + GetSignatureAlgorithm(cert);
 	BIO_write(out, pre.CStr(), pre.GetLength());