diff --git a/src/gui/src/SettingsDialog.cpp b/src/gui/src/SettingsDialog.cpp
index bcaa2263..dbd3ef27 100644
--- a/src/gui/src/SettingsDialog.cpp
+++ b/src/gui/src/SettingsDialog.cpp
@@ -37,7 +37,8 @@ SettingsDialog::SettingsDialog(QWidget* parent, AppConfig& config) :
 	QDialog(parent, Qt::WindowTitleHint | Qt::WindowSystemMenuHint),
 	Ui::SettingsDialogBase(),
 	m_AppConfig(config),
-	m_SuppressElevateWarning(false)
+	m_SuppressElevateWarning(false),
+	m_SuppressEncryptionWarning(false)
 {
 	setupUi(this);
 
@@ -68,7 +69,9 @@ SettingsDialog::SettingsDialog(QWidget* parent, AppConfig& config) :
 		m_pCheckBoxEnableCrypto->setChecked(false);
 	}
 	else {
+		m_SuppressEncryptionWarning = true;
 		m_pCheckBoxEnableCrypto->setChecked(m_AppConfig.getCryptoEnabled());
+		m_SuppressEncryptionWarning = false;
 	}
 }
 
@@ -83,6 +86,7 @@ void SettingsDialog::accept()
 	appConfig().setLanguage(m_pComboLanguage->itemData(m_pComboLanguage->currentIndex()).toString());
 	appConfig().setElevateMode(m_pCheckBoxElevateMode->isChecked());
 	appConfig().setAutoHide(m_pCheckBoxAutoHide->isChecked());
+	appConfig().setCryptoEnabled(m_pCheckBoxEnableCrypto->isChecked());
 	appConfig().saveSettings();
 	QDialog::accept();
 }
@@ -164,5 +168,17 @@ void SettingsDialog::on_m_pCheckBoxElevateMode_toggled(bool checked)
 
 void SettingsDialog::on_m_pCheckBoxEnableCrypto_toggled(bool checked)
 {
-	m_AppConfig.setCryptoEnabled(checked);
+	if (checked && !m_SuppressEncryptionWarning) {
+		int r = QMessageBox::warning(
+			this, tr("Synergy SSL Encryption"),
+			tr("Are you sure you want to enable SSL encryption?\n\n"
+			   "This allows Synergy to establish a secure connection, "
+			   "but can slow down the data transfer of clipboard and file."),
+			QMessageBox::Yes | QMessageBox::No);
+
+		if (r != QMessageBox::Yes) {
+			m_pCheckBoxEnableCrypto->setChecked(false);
+			return;
+		}
+	}
 }
diff --git a/src/gui/src/SettingsDialog.h b/src/gui/src/SettingsDialog.h
index 8ab2e1e0..dc0d1bb2 100644
--- a/src/gui/src/SettingsDialog.h
+++ b/src/gui/src/SettingsDialog.h
@@ -47,6 +47,7 @@ class SettingsDialog : public QDialog, public Ui::SettingsDialogBase
 		SynergyLocale m_Locale;
 		CoreInterface m_CoreInterface;
 		bool m_SuppressElevateWarning;
+		bool m_SuppressEncryptionWarning;
 
 	private slots:
 		void on_m_pCheckBoxEnableCrypto_toggled(bool checked);