diff --git a/src/shared/dto/baseline-data.dto.ts b/src/shared/dto/baseline-data.dto.ts
index e648455c..64340e60 100644
--- a/src/shared/dto/baseline-data.dto.ts
+++ b/src/shared/dto/baseline-data.dto.ts
@@ -26,7 +26,7 @@ export class BaselineDataDto {
   @IsString()
   device?: string;
 
-  @ApiProperty()
+  @ApiPropertyOptional()
   @IsOptional()
   @IsString()
   customTags?: string;
diff --git a/src/shared/static/static.service.ts b/src/shared/static/static.service.ts
index 09aad0c4..d0947aa0 100644
--- a/src/shared/static/static.service.ts
+++ b/src/shared/static/static.service.ts
@@ -23,6 +23,12 @@ export class StaticService {
   }
 
   saveImage(type: 'screenshot' | 'diff' | 'baseline', imageBuffer: Buffer): string {
+    try {
+      new PNG().parse(imageBuffer);
+    } catch (ex) {
+      throw new Error('Cannot parse image as PNG file');
+    }
+
     const { imageName, imagePath } = this.generateNewImage(type);
     writeFileSync(imagePath, imageBuffer);
     return imageName;