diff --git a/build.rs b/build.rs
index af62d14..8aed6c0 100644
--- a/build.rs
+++ b/build.rs
@@ -2,16 +2,27 @@ use sha2::{Digest, Sha256};
 use walkdir::WalkDir;
 
 fn main() -> anyhow::Result<()> {
-    let mut hasher = Sha256::new();
+    let mut css_hasher = Sha256::new();
     for entry in WalkDir::new("static/css") {
         let entry = entry.unwrap();
         if entry.file_type().is_file() {
-            hasher.update(std::fs::read_to_string(entry.path())?);
+            css_hasher.update(std::fs::read_to_string(entry.path())?);
         }
     }
 
-    let hash = hasher.finalize();
-    println!("cargo:rustc-env=CSS_VERSION={:x}", hash);
+    let css_hash = css_hasher.finalize();
+    println!("cargo:rustc-env=CSS_VERSION={:x}", css_hash);
+
+    let mut js_hasher = Sha256::new();
+    for entry in WalkDir::new("static/js") {
+        let entry = entry.unwrap();
+        if entry.file_type().is_file() {
+            js_hasher.update(std::fs::read_to_string(entry.path())?);
+        }
+    }
+
+    let js_hash = js_hasher.finalize();
+    println!("cargo:rustc-env=JS_VERSION={:x}", js_hash);
 
     Ok(())
 }
diff --git a/src/main.rs b/src/main.rs
index 56eb7c8..8a64720 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -33,6 +33,7 @@ pub struct Context {
 }
 
 const CSS_VERSION: &str = std::env!("CSS_VERSION");
+const JS_VERSION: &str = std::env!("JS_VERSION");
 
 struct TplContext<'a> {
     is_admin: bool,
@@ -42,6 +43,7 @@ struct TplContext<'a> {
     err_msg: Vec<String>,
     warning_msg: Vec<String>,
     css_version: &'a str,
+    js_version: &'a str,
 }
 
 impl<'a> TplContext<'a> {
@@ -54,6 +56,7 @@ impl<'a> TplContext<'a> {
             err_msg: session.err_msg.drain(..).collect(),
             warning_msg: session.warning_msg.drain(..).collect(),
             css_version: CSS_VERSION,
+            js_version: JS_VERSION,
         };
 
         session
diff --git a/templates/base.html b/templates/base.html
index ee32d81..d2a3d74 100644
--- a/templates/base.html
+++ b/templates/base.html
@@ -57,7 +57,7 @@
                 {% block main %}{% endblock main %}
             </main>
         </div>
-        <script src="/static/js/time.js" defer></script>
+        <script src="/static/js/time.js?{{ base.js_version}}" defer></script>
         {% block scripts %}
         {% endblock scripts %}
     </body>
diff --git a/templates/room.html b/templates/room.html
index a08292d..be41cc2 100644
--- a/templates/room.html
+++ b/templates/room.html
@@ -131,7 +131,7 @@
 </script>
 <script src="/static/contrib/highlight.js/highlight.min.js" defer></script>
 <script src="/static/contrib/highlight.js/yaml.min.js" defer></script>
-<script src="/static/js/viewer.js" defer></script>
+<script src="/static/js/viewer.js?{{ base.js_version }}" defer></script>
 {% endblock %}
 
 {% block styles %}