diff --git a/CHANGELOG.md b/CHANGELOG.md
index e10fc6d..c743dae 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,10 @@
 # Change Log
 
+## [1.5.1] (2022-11-09)
+
+### Fixed
+- Problem with iterating over undefined
+
 ## [1.5.0] (2022-08-09)
 
 ### Changed
@@ -91,6 +96,7 @@ Display a hover with following conversions of the pointed hexadecimal value:
 
 
 
+[1.5.1]: https://github.com/mateuszchudyk/vscode-hexinspector/compare/v1.5.0...v1.5.1
 [1.5.0]: https://github.com/mateuszchudyk/vscode-hexinspector/compare/v1.4.0...v1.5.0
 [1.4.0]: https://github.com/mateuszchudyk/vscode-hexinspector/compare/v1.3.0...v1.4.0
 [1.3.0]: https://github.com/mateuszchudyk/vscode-hexinspector/compare/v1.2.0...v1.3.0
diff --git a/package.json b/package.json
index 473bd45..10beae9 100644
--- a/package.json
+++ b/package.json
@@ -2,7 +2,7 @@
 	"name": "hexinspector",
 	"displayName": "HexInspector",
 	"description": "Provides fast and easy way to peek other forms of a hexadecimal/decimal/binary value",
-	"version": "1.5.0",
+	"version": "1.5.1",
 	"publisher": "mateuszchudyk",
 	"license": "MIT",
 	"repository": {
diff --git a/src/extension.ts b/src/extension.ts
index bb7f5bd..5e7a96b 100644
--- a/src/extension.ts
+++ b/src/extension.ts
@@ -19,7 +19,7 @@ export function activate(context: vscode.ExtensionContext) {
             }
 
             let bytes: Uint8Array;
-            let formsMap : input_handlers.MapFormToFunction;
+            let formsMap: input_handlers.MapFormToFunction;
 
             for (let inputDataType of inputDataTypes) {
                 let inputHandler = input_handlers.createInputHandler(inputDataType);
@@ -34,13 +34,13 @@ export function activate(context: vscode.ExtensionContext) {
                 formsMap = inputHandler.getFormsMap();
             }
 
-            let formMaxLength = 0;
-            for (let form of forms) {
-                if (form in formsMap)
-                    formMaxLength = Math.max(formMaxLength, form.length);
-            }
-
             if (bytes) {
+                let formMaxLength = 0;
+                for (let form of forms) {
+                    if (form in formsMap)
+                        formMaxLength = Math.max(formMaxLength, form.length);
+                }
+
                 let length = bytes.length;
                 let message = 'HexInspector: ' + word + ' (' + length + 'B)\n\n';
                 for (let form of forms) {