diff --git a/src/gameflow.h b/src/gameflow.h
index 2832611..d8ef555 100644
--- a/src/gameflow.h
+++ b/src/gameflow.h
@@ -457,8 +457,8 @@ namespace TR {
             case VER_TR2 : return LVL_TR2_ASSAULT;
             case VER_TR3 : return LVL_TR3_HOUSE;
         }
-        return LVL_TR1_TITLE;
         ASSERT(false);
+        return LVL_MAX;
     }
 
     LevelID getStartId(Version version) {
@@ -467,8 +467,8 @@ namespace TR {
             case VER_TR2 : return LVL_TR2_WALL;
             case VER_TR3 : return LVL_TR3_JUNGLE;
         }
-        return LVL_MAX;
         ASSERT(false);
+        return LVL_MAX;
     }
 
     LevelID getEndId(Version version) {
@@ -477,8 +477,8 @@ namespace TR {
             case VER_TR2 : return LVL_TR2_HOUSE;
             case VER_TR3 : return LVL_TR3_CHAMBER;
         }
-        return LVL_MAX;
         ASSERT(false);
+        return LVL_MAX;
     }
 
     bool isCutsceneLevel(LevelID id) {
@@ -546,7 +546,7 @@ namespace TR {
             }
         } else {
             strcpy(dst, "level/");
-            if (version & VER_TR1) strcat(dst, "1/");
+            if ((version & VER_TR1) || version == VER_UNKNOWN) strcat(dst, "1/");
             if (version & VER_TR2) strcat(dst, "2/");
             if (version & VER_TR3) strcat(dst, "3/");
             strcat(dst, LEVEL_INFO[id].name);
diff --git a/src/platform/nix/build.sh b/src/platform/nix/build.sh
index a3dabf0..f84633e 100755
--- a/src/platform/nix/build.sh
+++ b/src/platform/nix/build.sh
@@ -1,3 +1,3 @@
 set -e
-clang++ -std=c++11 -Os -s -fno-exceptions -fno-rtti -ffunction-sections -fdata-sections -Wl,--gc-sections -DNDEBUG main.cpp ../../libs/stb_vorbis/stb_vorbis.c ../../libs/minimp3/minimp3.cpp ../../libs/tinf/tinflate.c -I../../ -o../../../bin/OpenLara -lX11 -lGL -lm -lpthread -lpulse-simple -lpulse
+clang++ -std=c++11 -Os -s -fno-exceptions -fno-rtti -ffunction-sections -fdata-sections -Wl,--gc-sections -DNDEBUG -D_POSIX_THREADS -D_POSIX_READER_WRITER_LOCKS main.cpp ../../libs/stb_vorbis/stb_vorbis.c ../../libs/minimp3/minimp3.cpp ../../libs/tinf/tinflate.c -I../../ -o../../../bin/OpenLara -lX11 -lGL -lm -lpthread -lpulse-simple -lpulse
 strip ../../../bin/OpenLara --strip-all --remove-section=.comment --remove-section=.note