diff --git a/.changeset/fix-hashmap-protobuf.md b/.changeset/fix-hashmap-protobuf.md
new file mode 100644
index 0000000..c700d06
--- /dev/null
+++ b/.changeset/fix-hashmap-protobuf.md
@@ -0,0 +1,5 @@
+---
+"@codama/renderers-vixen-parser": patch
+---
+
+- Fix broken protobuf generation for `hashMap` fields in IDL.
\ No newline at end of file
diff --git a/src/getProtoTypeManifestVisitor.ts b/src/getProtoTypeManifestVisitor.ts
index bb0cadc..e45ddf8 100644
--- a/src/getProtoTypeManifestVisitor.ts
+++ b/src/getProtoTypeManifestVisitor.ts
@@ -280,7 +280,7 @@ export function getProtoTypeManifestVisitor(options: {
                     return {
                         imports: new ImportMap(),
                         nestedStructs: [],
-                        type: `map<${key.type}, ${value.type}> = 1`,
+                        type: `map<${key.type}, ${value.type}>`,
                     };
                 },