diff --git a/src/plugins/tls/securetransport/qtls_st.cpp b/src/plugins/tls/securetransport/qtls_st.cpp
index 48b7f3364f8..ff431dabd17 100644
--- a/src/plugins/tls/securetransport/qtls_st.cpp
+++ b/src/plugins/tls/securetransport/qtls_st.cpp
@@ -817,17 +817,32 @@ bool TlsCryptographSecureTransport::setSessionCertificate(QString &errorDescript
         const void *values[2] = { password };
         CFIndex nKeys = 1;
 #ifdef Q_OS_MACOS
-        bool envOk = false;
-        const int env = qEnvironmentVariableIntValue("QT_SSL_USE_TEMPORARY_KEYCHAIN", &envOk);
-        if (envOk && env) {
-            static const EphemeralSecKeychain temporaryKeychain;
-            if (temporaryKeychain.keychain) {
-                nKeys = 2;
-                keys[1] = kSecImportExportKeychain;
-                values[1] = temporaryKeychain.keychain;
+#if QT_MACOS_IOS_PLATFORM_SDK_EQUAL_OR_ABOVE(150000, 180000)
+        // Starting from macOS 15 our temporary keychain is ignored.
+        // We have to use kSecImportToMemoryOnly/kCFBooleanTrue key/value
+        // instead. This key is "memory" but looks like Security framework
+        // does not compare strings, but pointers instead, so we need an actual
+        // key/constant.
+        if (__builtin_available(macOS 15, *)) {
+            nKeys = 2;
+            keys[1] = kSecImportToMemoryOnly;
+            values[1] = kCFBooleanTrue;
+        } else {
+#else
+        {
+#endif
+            bool envOk = false;
+            const int env = qEnvironmentVariableIntValue("QT_SSL_USE_TEMPORARY_KEYCHAIN", &envOk);
+            if (envOk && env) {
+                static const EphemeralSecKeychain temporaryKeychain;
+                if (temporaryKeychain.keychain) {
+                    nKeys = 2;
+                    keys[1] = kSecImportExportKeychain;
+                    values[1] = temporaryKeychain.keychain;
+                }
             }
         }
-#endif
+#endif // Q_OS_MACOS
         QCFType<CFDictionaryRef> options = CFDictionaryCreate(nullptr, keys, values, nKeys,
                                                               nullptr, nullptr);
         QCFType<CFArrayRef> items;