diff --git a/examples/aishell/s1/local/export.sh b/examples/aishell/s1/local/export.sh
index 1b19d5720b731bed8006d1faed03176dd4ba0c56..d171899cdbf4220436bb71ad07e3a1a5e9ea8bc2 100755
--- a/examples/aishell/s1/local/export.sh
+++ b/examples/aishell/s1/local/export.sh
@@ -13,7 +13,7 @@ ckpt_path_prefix=$2
 jit_model_export_path=$3
 
 device=gpu
-if [ ngpu == 0 ];then
+if [ ${ngpu} == 0 ];then
     device=cpu
 fi