diff --git a/common/changes/@cadl-lang/openapi3/fixOpenApiRefSafeName_2022-04-18-23-36.json b/common/changes/@cadl-lang/openapi3/fixOpenApiRefSafeName_2022-04-18-23-36.json
new file mode 100644
index 00000000000..3e674c0f189
--- /dev/null
+++ b/common/changes/@cadl-lang/openapi3/fixOpenApiRefSafeName_2022-04-18-23-36.json
@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "@cadl-lang/openapi3",
+      "comment": "Fix issue with OpenAPI emitter not sanitizing parameter names in reference identifiers",
+      "type": "patch"
+    }
+  ],
+  "packageName": "@cadl-lang/openapi3"
+}
\ No newline at end of file
diff --git a/packages/openapi3/src/openapi.ts b/packages/openapi3/src/openapi.ts
index 32b4b741437..99188be1463 100644
--- a/packages/openapi3/src/openapi.ts
+++ b/packages/openapi3/src/openapi.ts
@@ -613,9 +613,8 @@ function createOAPIEmitter(program: Program, options: OpenAPIEmitterOptions) {
     }
 
     // Try to shorten the type name to exclude the top-level service namespace
-    let baseKey = getRefSafeName(key);
     if (serviceNamespace && key.startsWith(serviceNamespace)) {
-      baseKey = key.substring(serviceNamespace.length + 1);
+      const baseKey = key.substring(serviceNamespace.length + 1);
 
       // If no parameter exists with the shortened name, use it, otherwise use the fully-qualified name
       if (!root.components.parameters[baseKey] || isQualifiedParamName) {
@@ -623,7 +622,7 @@ function createOAPIEmitter(program: Program, options: OpenAPIEmitterOptions) {
       }
     }
 
-    return key;
+    return getRefSafeName(key);
   }
 
   function getSchemaForType(type: Type) {
@@ -1210,7 +1209,7 @@ function isRefSafeName(name: string) {
 }
 
 function getRefSafeName(name: string) {
-  return name.replace(/^[A-Za-z0-9-_.]/g, "_");
+  return name.replace(/[^A-Za-z0-9-_.]/g, "_");
 }
 
 function prettierOutput(output: string) {
diff --git a/packages/openapi3/test/test-openapi-output.ts b/packages/openapi3/test/test-openapi-output.ts
index 8315c4901cb..1c0c8b5a6ea 100644
--- a/packages/openapi3/test/test-openapi-output.ts
+++ b/packages/openapi3/test/test-openapi-output.ts
@@ -937,4 +937,29 @@ describe("openapi3: extension decorator", () => {
     strictEqual(oapi.components.parameters.PetId.schema.format, "UUID");
     strictEqual(oapi.components.parameters.PetId.schema.pattern, "^[a-zA-Z0-9-]{3,24}$");
   });
+
+  it("correctly sanitizes parameter names", async () => {
+    const oapi = await openApiFor(
+      `
+      model Pet extends Pet$Id {
+        name: string;
+      }
+      model Pet$Id {
+        @path
+        petId: string;
+      }
+      @route("/Pets")
+      namespace root {
+        @get()
+        op get(... Pet$Id): Pet;
+      }
+      `
+    );
+    ok(oapi.paths["/Pets/{petId}"].get);
+    strictEqual(
+      oapi.paths["/Pets/{petId}"].get.parameters[0]["$ref"],
+      "#/components/parameters/Pet_Id"
+    );
+    strictEqual(oapi.components.parameters.Pet_Id.name, "petId");
+  });
 });