diff --git a/src/__test__/trpcToOpenApi.test.ts b/src/__test__/trpcToOpenApi.test.ts
index b9e2aec..02ea2e9 100644
--- a/src/__test__/trpcToOpenApi.test.ts
+++ b/src/__test__/trpcToOpenApi.test.ts
@@ -204,6 +204,7 @@ describe("trpcToOpenApi", () => {
     it("includes headers in every endpoint", () => {
       const t = initTRPC.create();
       const router = t.router({
+        ping: t.procedure.query(() => undefined),
         createThing: t.procedure
           .input(z.object({ name: z.string() }))
           .mutation(() => undefined),
@@ -242,6 +243,10 @@ describe("trpcToOpenApi", () => {
         { $ref: "#/components/parameters/MyHeader" },
       ];
 
+      expect(openApiSpec.paths?.["/ping"]?.get?.parameters).toEqual(
+        expectedHeaderReferences,
+      );
+
       expect(openApiSpec.paths?.["/createThing"]?.post?.parameters).toEqual(
         expectedHeaderReferences,
       );
diff --git a/src/trpcToOpenApi.ts b/src/trpcToOpenApi.ts
index 1730f77..95904c5 100644
--- a/src/trpcToOpenApi.ts
+++ b/src/trpcToOpenApi.ts
@@ -137,13 +137,13 @@ function getPathsForProcedure({
         content,
       };
     }
+  }
 
-    if (additionalParameters != null) {
-      operation.parameters = [
-        ...(operation.parameters ?? []),
-        ...(additionalParameters ?? []),
-      ];
-    }
+  if (additionalParameters != null) {
+    operation.parameters = [
+      ...(operation.parameters ?? []),
+      ...(additionalParameters ?? []),
+    ];
   }
 
   return {