diff --git a/src/main/resources/templates/pages/depository/table-stock.html b/src/main/resources/templates/pages/depository/table-stock.html
index 3b3cdeb3..f7bc8dad 100644
--- a/src/main/resources/templates/pages/depository/table-stock.html
+++ b/src/main/resources/templates/pages/depository/table-stock.html
@@ -113,7 +113,7 @@
 
     }
 
-    let socket;
+    let socket = null;
 
     let newIndexShade;
 
diff --git a/src/main/resources/templates/pages/material/material-out.html b/src/main/resources/templates/pages/material/material-out.html
index 449f303b..1cbd8444 100644
--- a/src/main/resources/templates/pages/material/material-out.html
+++ b/src/main/resources/templates/pages/material/material-out.html
@@ -134,7 +134,7 @@
 
     }
 
-    let socket;
+    let socket = null;
 
     let newIndexShade;
 
diff --git a/src/main/resources/templates/pages/materialtype/materialType_view.html b/src/main/resources/templates/pages/materialtype/materialType_view.html
index dd6f34dd..e1c2f92c 100644
--- a/src/main/resources/templates/pages/materialtype/materialType_view.html
+++ b/src/main/resources/templates/pages/materialtype/materialType_view.html
@@ -108,7 +108,7 @@
 
     }
 
-    let socket;
+    let socket = null;
 
     let newIndexShade;