diff --git a/czkawka_core/src/broken_files.rs b/czkawka_core/src/broken_files.rs
index 20ac886..cd97872 100644
--- a/czkawka_core/src/broken_files.rs
+++ b/czkawka_core/src/broken_files.rs
@@ -663,7 +663,7 @@ fn load_cache_from_file(text_messages: &mut Messages) -> Option<HashMap<String,
 
 fn check_extension_avaibility(file_name_lowercase: &str) -> TypeOfFile {
     // Checking allowed image extensions
-    let allowed_image_extensions = [".jpg", ".jpeg", ".png", ".bmp", ".ico", ".tiff", ".pnm", ".tga", ".ff", ".gif"];
+    let allowed_image_extensions = [".jpg", ".jpeg", ".png", ".bmp", ".tiff", ".pnm", ".tga", ".ff", ".gif"];
     let allowed_archive_zip_extensions = [".zip"]; // Probably also should work [".xz", ".bz2"], but from my tests they not working
     let allowed_audio_extensions = [".mp3", ".flac", ".wav", ".ogg"]; // Probably also should work [".xz", ".bz2"], but from my tests they not working
     if allowed_image_extensions.iter().any(|e| file_name_lowercase.ends_with(e)) {
diff --git a/czkawka_core/src/similar_images.rs b/czkawka_core/src/similar_images.rs
index 2dd84ec..28b42c0 100644
--- a/czkawka_core/src/similar_images.rs
+++ b/czkawka_core/src/similar_images.rs
@@ -265,8 +265,8 @@ impl SimilarImages {
                     .to_lowercase();
 
                     // Checking allowed image extensions
-                    let allowed_image_extensions = ["jpg", "jpeg", "png", "bmp", "ico", "tiff", "pnm", "tga", "ff", "gif"];
-                    if !allowed_image_extensions.iter().any(|e| file_name_lowercase.ends_with(format!(".{}", e).as_str())) {
+                    let allowed_image_extensions = [".jpg", ".jpeg", ".png", ".bmp", ".tiff", ".pnm", ".tga", ".ff", ".gif"];
+                    if !allowed_image_extensions.iter().any(|e| file_name_lowercase.ends_with(e)) {
                         continue 'dir;
                     }
 
diff --git a/instructions/Instruction.md b/instructions/Instruction.md
index b31faee..18ff29d 100644
--- a/instructions/Instruction.md
+++ b/instructions/Instruction.md
@@ -113,7 +113,7 @@ Then, for each selected tag by which we want to search for duplicates, we perfor
 ### Similar Images
 It is a tool for finding similar images that differ e.g. in watermark, size etc.
 
-The tool first collects images with specific extensions that can be checked - `["jpg", "png", "bmp", "ico", "tiff"]`.
+The tool first collects images with specific extensions that can be checked - `[".jpg", ".jpeg", ".png", ".bmp", ".tiff", ".pnm", ".tga", ".ff", ".gif"]`.
 
 Next cached data are loaded from file to prevent hashing twice same file.  
 Automatically cache which points to non existing data is deleted.