diff --git a/CHANGELOG.md b/CHANGELOG.md
index 95d3adad88..5d6c095088 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,8 @@ Changes:
 - Explicit param length checks for all generic portable overrides
 - Re-export `ScProvider` in `@polkadot/api`, aligning with `{Http, Ws}Provider`
 - Expose `WellKnownChain` as static on `ScProvider.WellKnownChain`
+- Checks for non-available interface types & runtime/rpc definitions
+- Ensure `.entries/.keys` arguments is less than map-entry query
 - Add Polkadot 9260 upgrade block
 - Add Westend 9271 upgrade block
 - Update to latest Substrate metadata
diff --git a/packages/types/src/metadata/decorate/storage/createFunction.ts b/packages/types/src/metadata/decorate/storage/createFunction.ts
index fee860d0eb..efa972c1c9 100644
--- a/packages/types/src/metadata/decorate/storage/createFunction.ts
+++ b/packages/types/src/metadata/decorate/storage/createFunction.ts
@@ -219,8 +219,8 @@ function extendPrefixedMap (registry: Registry, itemFn: CreateItemFn, storageFn:
   const { meta: { type }, method, section } = itemFn;
 
   storageFn.iterKey = extendHeadMeta(registry, itemFn, storageFn, (...args: unknown[]): Raw => {
-    if (args.length && (type.isPlain || (args.length > type.asMap.hashers.length))) {
-      throw new Error(`Iteration ${stringCamelCase(section || 'unknown')}.${stringCamelCase(method || 'unknown')} needs arguments to be at least one less than the full arguments, found [${args.join(', ')}]`);
+    if (args.length && (type.isPlain || (args.length >= type.asMap.hashers.length))) {
+      throw new Error(`Iteration of ${stringCamelCase(section || 'unknown')}.${stringCamelCase(method || 'unknown')} needs arguments to be at least one less than the full arguments, found [${args.join(', ')}]`);
     }
 
     if (args.length) {