diff --git a/code/ryzom/tools/client/ryzom_installer/src/installdialog.cpp b/code/ryzom/tools/client/ryzom_installer/src/installdialog.cpp
index 7198962ac..6ec2a49ed 100644
--- a/code/ryzom/tools/client/ryzom_installer/src/installdialog.cpp
+++ b/code/ryzom/tools/client/ryzom_installer/src/installdialog.cpp
@@ -35,17 +35,28 @@ CInstallDialog::CInstallDialog():QDialog()
 	// update default destination
 	onDestinationDefaultButtonClicked();
 
+#ifdef Q_OS_MAC
 	// check whether OS architecture is 32 or 64 bits
 	if (CConfigFile::has64bitsOS())
 	{
+		// 64 bits enbabled by default
 		clientArchGroupBox->setVisible(true);
 		clientArch64RadioButton->setChecked(true);
+		clientArch32RadioButton->setChecked(false);
 	}
 	else
 	{
+		// only 32 bits is available
 		clientArchGroupBox->setVisible(false);
+		clientArch64RadioButton->setChecked(false);
 		clientArch32RadioButton->setChecked(true);
 	}
+#else
+	// only 64 bits for OS X
+	clientArchGroupBox->setVisible(false);
+	clientArch64RadioButton->setChecked(true);
+	clientArch32RadioButton->setChecked(false);
+#endif
 
 	const CServer &server = CConfigFile::getInstance()->getServer();
 
diff --git a/code/ryzom/tools/client/ryzom_installer/src/migratedialog.cpp b/code/ryzom/tools/client/ryzom_installer/src/migratedialog.cpp
index 22e4f0ad2..f60abd95c 100644
--- a/code/ryzom/tools/client/ryzom_installer/src/migratedialog.cpp
+++ b/code/ryzom/tools/client/ryzom_installer/src/migratedialog.cpp
@@ -49,17 +49,28 @@ CMigrateDialog::CMigrateDialog():QDialog()
 	// update default destination
 	onDestinationDefaultButtonClicked();
 
+#ifdef Q_OS_MAC
 	// check whether OS architecture is 32 or 64 bits
 	if (CConfigFile::has64bitsOS())
 	{
+		// 64 bits enbabled by default
 		clientArchGroupBox->setVisible(true);
 		clientArch64RadioButton->setChecked(true);
+		clientArch32RadioButton->setChecked(false);
 	}
 	else
 	{
+		// only 32 bits is available
 		clientArchGroupBox->setVisible(false);
+		clientArch64RadioButton->setChecked(false);
 		clientArch32RadioButton->setChecked(true);
 	}
+#else
+	// only 64 bits for OS X
+	clientArchGroupBox->setVisible(false);
+	clientArch64RadioButton->setChecked(true);
+	clientArch32RadioButton->setChecked(false);
+#endif
 
 	const CServer &server = CConfigFile::getInstance()->getServer();