diff --git a/install.sh b/install.sh
index 2889b235..c8959d43 100644
--- a/install.sh
+++ b/install.sh
@@ -12,7 +12,8 @@ echo "***********************************************"
 
 # Check available capacity
 dir_avail() {
-    df -P $2 "${1:-.}" 2>/dev/null | awk 'NR==2 {print $(NF-2)}'
+	df -h >/dev/null 2>&1 && h="$2"
+    df -P $h "${1:-.}" 2>/dev/null | awk 'NR==2 {print $(NF-2)}'
 }
 
 ckcmd() { #检查命令
diff --git a/scripts/libs/check_dir_avail.sh b/scripts/libs/check_dir_avail.sh
index 3b2bccff..03933ca6 100644
--- a/scripts/libs/check_dir_avail.sh
+++ b/scripts/libs/check_dir_avail.sh
@@ -1,5 +1,5 @@
 #检查目录剩余空间——$1:目标路径 $2:-h参数
 dir_avail() {
 	df -h >/dev/null 2>&1 && h="$2"
-    df -P $2 "${1:-.}" 2>/dev/null | awk 'NR==2 {print $(NF-2)}'
+    df -P $h "${1:-.}" 2>/dev/null | awk 'NR==2 {print $(NF-2)}'
 }
\ No newline at end of file