diff --git a/CHANGELOG.md b/CHANGELOG.md
index 46de676d5..0b82300de 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -18,6 +18,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 
 ### Fixed
 
+- Fixed the `SHEET` and `SHEETS` functions declaring their single argument as required, while both accept a zero-argument call.
 - Fixed the behavior of `MATCH`, `VLOOKUP`, `HLOOKUP`, and `XLOOKUP` functions when the search range contained empty cells. [#1697](https://github.com/handsontable/hyperformula/pull/1697)
 - Fixed the `VLOOKUP`, `HLOOKUP`, and `XLOOKUP` functions to return `0` instead of an empty value when the matched cell in the result range is empty. [#1697](https://github.com/handsontable/hyperformula/pull/1697)
 - Fixed the page freezing when entering a long string of digits containing a non-digit character near the end (e.g. `012...789a` or `012...789 123`) into a cell. [#1520](https://github.com/handsontable/hyperformula/issues/1520)
diff --git a/src/interpreter/plugin/InformationPlugin.ts b/src/interpreter/plugin/InformationPlugin.ts
index 481522107..8c10ac05e 100644
--- a/src/interpreter/plugin/InformationPlugin.ts
+++ b/src/interpreter/plugin/InformationPlugin.ts
@@ -137,7 +137,7 @@ export class InformationPlugin extends FunctionPlugin implements FunctionPluginT
     'SHEET': {
       method: 'sheet',
       parameters: [
-        {argumentType: FunctionArgumentType.STRING}
+        {argumentType: FunctionArgumentType.STRING, optionalArg: true}
       ],
       doesNotNeedArgumentsToBeComputed: true,
       vectorizationForbidden: true,
@@ -145,7 +145,7 @@ export class InformationPlugin extends FunctionPlugin implements FunctionPluginT
     'SHEETS': {
       method: 'sheets',
       parameters: [
-        {argumentType: FunctionArgumentType.STRING}
+        {argumentType: FunctionArgumentType.STRING, optionalArg: true}
       ],
       doesNotNeedArgumentsToBeComputed: true,
       vectorizationForbidden: true,