diff --git a/.github/workflows/website.yml b/.github/workflows/website.yml
index eb0540480..8043a7a03 100644
--- a/.github/workflows/website.yml
+++ b/.github/workflows/website.yml
@@ -113,7 +113,7 @@ jobs:
         echo "uutils WASM build: ${commit_short} (${commit_date})"
 
     - name: Upload uutils WASM artifact
-      uses: actions/upload-artifact@v8
+      uses: actions/upload-artifact@v7
       with:
         name: wasm-coreutils
         path: wasm-out
@@ -214,7 +214,7 @@ jobs:
         echo "${{ matrix.name }} WASM build: ${s} (${d})"
 
     - name: Upload ${{ matrix.name }} WASM artifact
-      uses: actions/upload-artifact@v8
+      uses: actions/upload-artifact@v7
       with:
         name: wasm-${{ matrix.name }}
         path: wasm-out
@@ -389,7 +389,7 @@ jobs:
       run: rm -f public/js/wasm-terminal.test.html
 
     - name: Upload artifact for checking the output
-      uses: actions/upload-artifact@v8
+      uses: actions/upload-artifact@v7
       with:
         path: ./public
 
diff --git a/static/js/wasm-terminal.js b/static/js/wasm-terminal.js
index fd5b9afb7..1f79bbeb2 100644
--- a/static/js/wasm-terminal.js
+++ b/static/js/wasm-terminal.js
@@ -638,10 +638,30 @@ async function executeCommandLine(line) {
     }
 
     try {
+      // sed's script argument is a program, not a path — it must NOT go through
+      // resolvePath, which normalizes path segments and would strip a trailing
+      // delimiter (e.g. `s/world/there/` -> `s/world/there`, breaking the `s`
+      // command). Collect the indices of any sed script arguments to skip.
+      const sedScriptIndices = new Set();
+      if (cmd === "sed") {
+        let scriptFromFlag = false;
+        for (let i = 1; i < args.length; i++) {
+          const a = args[i];
+          if (a === "-e" || a === "-f") { sedScriptIndices.add(i + 1); scriptFromFlag = true; i++; continue; }
+          if (a.startsWith("-e") || a.startsWith("-f")) { scriptFromFlag = true; } // combined form, e.g. -e's/a/b/'
+        }
+        // Without -e/-f, the script is the first non-option argument.
+        if (!scriptFromFlag) {
+          for (let i = 1; i < args.length; i++) {
+            if (!args[i].startsWith("-")) { sedScriptIndices.add(i); break; }
+          }
+        }
+      }
       // Resolve relative paths using the virtual cwd
       const resolvedArgs = args.map((arg, i) => {
         if (i === 0) return arg; // command name
         if (arg.startsWith("-")) return arg; // flag
+        if (sedScriptIndices.has(i)) return arg; // sed script, not a path
         return resolvePath(arg);
       });
       // If the command takes a default path (like ls) and no path args