diff --git a/ports/install.sh b/ports/install.sh
index 14699f9cfa..9a9694e695 100755
--- a/ports/install.sh
+++ b/ports/install.sh
@@ -6,7 +6,7 @@ if (( $# != 1 )); then
 fi
 
 if [[ -z $BANAN_ROOT_DIR ]]; then
-	BANAN_ROOT_DIR="$(realpath $(dirname $(realpath $0))/..)"
+	export BANAN_ROOT_DIR="$(realpath $(dirname $(realpath $0))/..)"
 fi
 
 source "$BANAN_ROOT_DIR/script/config.sh"
@@ -29,6 +29,8 @@ export OBJDUMP="$BANAN_TOOLCHAIN_TRIPLE-objdump"
 export STRIP="$BANAN_TOOLCHAIN_TRIPLE-strip"
 export CXXFILT="$BANAN_TOOLCHAIN_TRIPLE-c++filt"
 
+export CMAKE_TOOLCHAIN_FILE="$BANAN_TOOLCHAIN_DIR/Toolchain.txt"
+
 pushd "$BANAN_ROOT_DIR" >/dev/null
 ./bos all && ./bos install || exit 1
 popd >/dev/null
diff --git a/toolchain/Toolchain.txt b/toolchain/Toolchain.txt
index 8acce806e7..5b12ce4f70 100644
--- a/toolchain/Toolchain.txt
+++ b/toolchain/Toolchain.txt
@@ -13,12 +13,21 @@ if (NOT DEFINED ENV{BANAN_SYSROOT_TAR})
 endif ()
 set(BANAN_SYSROOT_TAR $ENV{BANAN_SYSROOT_TAR})
 
-
-set(TOOLCHAIN_PREFIX ${CMAKE_SOURCE_DIR}/toolchain/local)
+if (NOT DEFINED ENV{BANAN_ROOT_DIR})
+	message(FATAL_ERROR "environment variable BANAN_ROOT_DIR not defined")
+endif ()
+set(TOOLCHAIN_PREFIX $ENV{BANAN_ROOT_DIR}/toolchain/local)
 
 set(CMAKE_SYSTEM_NAME banan-os)
 set(CMAKE_SYSTEM_PROCESSOR AMD64)
 
+set(CMAKE_SYSROOT ${BANAN_SYSROOT})
+
+set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
+set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
+set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
+set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE BOTH)
+
 set(CMAKE_CXX_STANDARD 20)
 set(CMAKE_CXX_STANDARD_REQUIRED True)
 set(CMAKE_CXX_COMPILER ${TOOLCHAIN_PREFIX}/bin/${BANAN_ARCH}-banan_os-g++)