diff --git a/engines/tsage/detection.cpp b/engines/tsage/detection.cpp
index 2687dc94f1b..a21c375847c 100644
--- a/engines/tsage/detection.cpp
+++ b/engines/tsage/detection.cpp
@@ -30,6 +30,7 @@ static const PlainGameDescriptor tSageGameTitles[] = {
 	{ "ringworld", "Ringworld: Revenge of the Patriarch" },
 	{ "blueforce", "Blue Force" },
 	{ "ringworld2", "Return to Ringworld" },
+	{ "protostar", "Protostar: War on the Frontier" },
 	{ "sherlock-logo", "The Lost Files of Sherlock Holmes (Logo)" },
 	{ 0, 0 }
 };
diff --git a/engines/tsage/detection_tables.h b/engines/tsage/detection_tables.h
index 400ff700330..6e998111432 100644
--- a/engines/tsage/detection_tables.h
+++ b/engines/tsage/detection_tables.h
@@ -254,7 +254,7 @@ static const tSageGameDescription gameDescriptions[] = {
 			AD_ENTRY1s("demops.rlb", "8a2aa522b4473bcc32e06371568c0d9a", 1019247),
 			Common::EN_ANY,
 			Common::kPlatformDOS,
-			ADGF_DEMO,
+			ADGF_DEMO | ADGF_UNSTABLE,
 			GUIO2(GUIO_NOSPEECH, GUIO_NOSFX)
 		},
 		GType_Ringworld,
@@ -269,7 +269,7 @@ static const tSageGameDescription gameDescriptions[] = {
 			AD_ENTRY1s("demops.rlb", "efe17413126b13228564f687d185a7ad", 511111),
 			Common::EN_ANY,
 			Common::kPlatformDOS,
-			ADGF_DEMO,
+			ADGF_DEMO | ADGF_UNSTABLE,
 			GUIO2(GUIO_NOSPEECH, GUIO_NOSFX)
 		},
 		GType_Ringworld,