diff --git a/cmake/flash/CMakeLists.txt b/cmake/flash/CMakeLists.txt
index e119e753985..4898fd0ecf6 100644
--- a/cmake/flash/CMakeLists.txt
+++ b/cmake/flash/CMakeLists.txt
@@ -6,6 +6,7 @@ list(APPEND ENV_VARS
   KERNEL_BIN_NAME=${KERNEL_BIN_NAME}
              ARCH=${ARCH}
        BOARD_NAME=${BOARD}
+             GDB=${CMAKE_GDB}
   )
 
 foreach(target flash debug debugserver)
diff --git a/cmake/toolchain-gcc.cmake b/cmake/toolchain-gcc.cmake
index 048a5a04ca6..475a1f50544 100644
--- a/cmake/toolchain-gcc.cmake
+++ b/cmake/toolchain-gcc.cmake
@@ -8,6 +8,7 @@ set(CMAKE_OBJDUMP      ${CROSS_COMPILE}objdump CACHE INTERNAL " " FORCE)
 set(CMAKE_AR           ${CROSS_COMPILE}ar      CACHE INTERNAL " " FORCE)
 set(CMAKE_RANLILB      ${CROSS_COMPILE}ranlib  CACHE INTERNAL " " FORCE)
 set(CMAKE_READELF      ${CROSS_COMPILE}readelf CACHE INTERNAL " " FORCE)
+set(CMAKE_GDB          ${CROSS_COMPILE}gdb     CACHE INTERNAL " " FORCE)
 
 assert_exists(CMAKE_READELF)