diff --git a/src/raspberrypi/rascsi_interface.proto b/src/raspberrypi/rascsi_interface.proto
index c552cb57..e21b3dda 100644
--- a/src/raspberrypi/rascsi_interface.proto
+++ b/src/raspberrypi/rascsi_interface.proto
@@ -169,9 +169,8 @@ message PbOperationParameter {
     string type = 3;
     // There is no specific set of values if empty
     repeated string values = 4;
-    // Optional default value
+    // Optional default value. If there is no default the value is mandatory.
     string default_value = 5;
-    bool is_mandatory = 6;
 }
 
 // The list of parameters supported by an operation
diff --git a/src/raspberrypi/rascsi_response.cpp b/src/raspberrypi/rascsi_response.cpp
index 110ad752..6053c2d7 100644
--- a/src/raspberrypi/rascsi_response.cpp
+++ b/src/raspberrypi/rascsi_response.cpp
@@ -457,7 +457,6 @@ PbOperationParameter *RascsiResponse::AddOperationParameter(PbOperationParameter
 	if (!default_value.empty()) {
 		parameter->set_default_value(default_value);
 	}
-	parameter->set_is_mandatory(default_value.empty());
 
 	return parameter;
 }
diff --git a/src/raspberrypi/rasctl_display.cpp b/src/raspberrypi/rasctl_display.cpp
index a746c39d..14f2a881 100644
--- a/src/raspberrypi/rasctl_display.cpp
+++ b/src/raspberrypi/rasctl_display.cpp
@@ -290,7 +290,7 @@ void RasctlDisplay::DisplayOperationInfo(const PbOperationInfo& operation_info)
 
 		for (const auto& parameter : operation.parameters()) {
 			cout << "    " << parameter.name() << ": " << parameter.type()
-				<< (parameter.is_mandatory() ? ", mandatory" : ", optional");
+				<< (parameter.default_value().empty() ? ", mandatory" : ", optional");
 			if (!parameter.description().empty()) {
 				cout << " (" << parameter.description().at("en") << ")";
 			}