diff --git a/docker/toolchain.cmake b/docker/toolchain.cmake
index 0017aac45..b469dceb6 100644
--- a/docker/toolchain.cmake
+++ b/docker/toolchain.cmake
@@ -40,7 +40,8 @@ endif()
 # if cross-compiling, we need to disable where the root path
 # is found and also provide our own sysroot
 if(DEFINED ENV{CROSS_SYSROOT})
-    set(CMAKE_FIND_ROOT_PATH "$ENV{CROSS_SYSROOT}" "${CMAKE_PREFIX_PATH}")
+    cmake_path(CONVERT "$ENV{CMAKE_PREFIX_PATH}" TO_CMAKE_PATH_LIST ENV_CMAKE_PREFIX_PATH)
+    set(CMAKE_FIND_ROOT_PATH "$ENV{CROSS_SYSROOT}" "${CMAKE_PREFIX_PATH}" "${ENV_CMAKE_PREFIX_PATH}")
     set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
     set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
     set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)