diff --git a/common/changes/@typespec/compiler/fix-caching-invalid_2023-10-30-22-27.json b/common/changes/@typespec/compiler/fix-caching-invalid_2023-10-30-22-27.json
new file mode 100644
index 0000000000..5945164bd2
--- /dev/null
+++ b/common/changes/@typespec/compiler/fix-caching-invalid_2023-10-30-22-27.json
@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "@typespec/compiler",
+      "comment": "",
+      "type": "none"
+    }
+  ],
+  "packageName": "@typespec/compiler"
+}
\ No newline at end of file
diff --git a/packages/compiler/src/core/checker.ts b/packages/compiler/src/core/checker.ts
index 2feba122bb..5bfaf2b144 100644
--- a/packages/compiler/src/core/checker.ts
+++ b/packages/compiler/src/core/checker.ts
@@ -2152,16 +2152,17 @@ export function createChecker(program: Program): Checker {
     mapper: TypeMapper | undefined,
     options?: Partial<SymbolResolutionOptions> | boolean
   ): Sym | undefined {
-    if (mapper === undefined && referenceSymCache.has(node)) {
-      return referenceSymCache.get(node);
-    }
-
     const resolvedOptions: SymbolResolutionOptions =
       typeof options === "boolean"
         ? { ...defaultSymbolResolutionOptions, resolveDecorators: options }
         : { ...defaultSymbolResolutionOptions, ...(options ?? {}) };
+    if (mapper === undefined && resolvedOptions.checkTemplateTypes && referenceSymCache.has(node)) {
+      return referenceSymCache.get(node);
+    }
     const sym = resolveTypeReferenceSymInternal(node, mapper, resolvedOptions);
-    referenceSymCache.set(node, sym);
+    if (resolvedOptions.checkTemplateTypes) {
+      referenceSymCache.set(node, sym);
+    }
     return sym;
   }
 
diff --git a/packages/compiler/test/checker/interface.test.ts b/packages/compiler/test/checker/interface.test.ts
index cce6337dec..cf9d5e63a4 100644
--- a/packages/compiler/test/checker/interface.test.ts
+++ b/packages/compiler/test/checker/interface.test.ts
@@ -438,6 +438,28 @@ describe("compiler: interfaces", () => {
         message: `Can't pass template arguments to non-templated type`,
       });
     });
+
+    // https://github.com/microsoft/typespec/pull/2617
+    it("can 'op is' a templated operation inside templated interface", async () => {
+      const { myBar } = (await runner.compile(`
+      interface Foo<A> {
+        bar<B>(input: A): B;
+      }
+
+      alias MyFoo = Foo<string>;
+      @test op myBar is MyFoo.bar<int32>;
+      `)) as {
+        myBar: Operation;
+      };
+
+      const input = myBar.parameters.properties.get("input")!.type;
+      strictEqual(input.kind, "Scalar" as const);
+      strictEqual(input.name, "string");
+
+      const returnType = myBar.returnType;
+      strictEqual(returnType.kind, "Scalar" as const);
+      strictEqual(returnType.name, "int32");
+    });
   });
 
   it("can decorate extended operations independently", async () => {