diff --git a/internal/linker/index.js b/internal/linker/index.js
index 87e8cc2c65..4f30625f9a 100644
--- a/internal/linker/index.js
+++ b/internal/linker/index.js
@@ -145,7 +145,7 @@ class Runfiles {
         if (path.isAbsolute(modulePath)) {
             return modulePath;
         }
-        const result = this._resolve(modulePath, '');
+        const result = this._resolve(modulePath, undefined);
         if (result) {
             return result;
         }
@@ -158,7 +158,7 @@ class Runfiles {
             const result = this.lookupDirectory(moduleBase);
             if (result) {
                 if (moduleTail) {
-                    const maybe = path.join(result, moduleTail);
+                    const maybe = path.join(result, moduleTail || '');
                     if (fs.existsSync(maybe)) {
                         return maybe;
                     }
@@ -169,7 +169,7 @@ class Runfiles {
             }
         }
         if (exports.runfiles.dir) {
-            const maybe = path.join(exports.runfiles.dir, moduleBase, moduleTail);
+            const maybe = path.join(exports.runfiles.dir, moduleBase, moduleTail || '');
             if (fs.existsSync(maybe)) {
                 return maybe;
             }
@@ -178,7 +178,7 @@ class Runfiles {
         if (dirname == '.') {
             return undefined;
         }
-        return this._resolve(dirname, path.join(path.basename(moduleBase), moduleTail));
+        return this._resolve(dirname, path.join(path.basename(moduleBase), moduleTail || ''));
     }
     resolveWorkspaceRelative(modulePath) {
         if (!this.workspace) {
diff --git a/internal/linker/link_node_modules.ts b/internal/linker/link_node_modules.ts
index 240f2c2ce1..848d9fff47 100644
--- a/internal/linker/link_node_modules.ts
+++ b/internal/linker/link_node_modules.ts
@@ -246,7 +246,7 @@ export class Runfiles {
     if (path.isAbsolute(modulePath)) {
       return modulePath;
     }
-    const result = this._resolve(modulePath, '');
+    const result = this._resolve(modulePath, undefined);
     if (result) {
       return result;
     }
@@ -255,12 +255,12 @@ export class Runfiles {
     throw e;
   }
 
-  _resolve(moduleBase: string, moduleTail: string): string|undefined {
+  _resolve(moduleBase: string, moduleTail: string|undefined): string|undefined {
     if (this.manifest) {
       const result = this.lookupDirectory(moduleBase);
       if (result) {
         if (moduleTail) {
-          const maybe = path.join(result, moduleTail);
+          const maybe = path.join(result, moduleTail || '');
           if (fs.existsSync(maybe)) {
             return maybe;
           }
@@ -270,7 +270,7 @@ export class Runfiles {
       }
     }
     if (runfiles.dir) {
-      const maybe = path.join(runfiles.dir, moduleBase, moduleTail);
+      const maybe = path.join(runfiles.dir, moduleBase, moduleTail || '');
       if (fs.existsSync(maybe)) {
         return maybe;
       }
@@ -280,7 +280,7 @@ export class Runfiles {
       // no match
       return undefined;
     }
-    return this._resolve(dirname, path.join(path.basename(moduleBase), moduleTail));
+    return this._resolve(dirname, path.join(path.basename(moduleBase), moduleTail || ''));
   }
 
   resolveWorkspaceRelative(modulePath: string) {