diff --git a/build_linux.sh b/build_linux.sh
index 677bc5df..09dde498 100644
--- a/build_linux.sh
+++ b/build_linux.sh
@@ -64,8 +64,6 @@ for (( i=1; i<=$#; i++ )); do
     BUILD_TOOL_LOBBY32=0
   elif [[ "$var" = "-tool-lobby-64" ]]; then
     BUILD_TOOL_LOBBY64=0
-  elif [[ "$var" = "+lowperf" ]]; then
-    BUILD_LOW_PERF=1
   elif [[ "$var" = "release" ]]; then
     BUILD_TYPE=0
   elif [[ "$var" = "debug" ]]; then
diff --git a/build_win.bat b/build_win.bat
index eaf6d638..7c57d693 100644
--- a/build_win.bat
+++ b/build_win.bat
@@ -55,8 +55,6 @@ set /a BUILD_TYPE=-1
     set /a BUILD_TOOL_FIND_ITFS=0
   ) else if "%~1"=="-tool-lobby" (
     set /a BUILD_TOOL_LOBBY=0
-  ) else if "%~1"=="+lowperf" (
-    set /a BUILD_LOW_PERF=1
   ) else if "%~1"=="-j" (
     call :get_parallel_threads_count %~2 || (
       call :err_msg "Invalid arg after -j, expected a number"