diff --git a/tools/env.sh b/tools/env.sh
index 7b21c968..daf02519 100755
--- a/tools/env.sh
+++ b/tools/env.sh
@@ -7,13 +7,13 @@ export PATH=$LUNA_ROOT/toolchain/x86-64-luna/bin:$LUNA_ROOT/toolchain/dist:$PATH
 
 export ARCH=${ARCH:-x86_64}
 
-if [ "$USE_NINJA" = "1" ]
+if [ "$USE_MAKE" = "1" ]
 then
-export BUILD=ninja
-export CMAKE_GEN=Ninja
-else
 export BUILD=make
 export CMAKE_GEN="Unix Makefiles"
+else
+export BUILD=ninja
+export CMAKE_GEN="Ninja"
 fi
 
 export BUILD_DIR=$LUNA_ROOT/build/$BUILD-$ARCH
\ No newline at end of file