diff --git a/otp.c b/otp.c
index 2c46d56..3d0fe87 100644
--- a/otp.c
+++ b/otp.c
@@ -2559,7 +2559,27 @@ int handle_file_encrypt(void) {
     
     int ascii_armor = (atoi(format_input) == 2) ? 1 : 0;
     
-    return encrypt_file(pad_input, input_file, NULL, ascii_armor);
+    // Generate default output filename
+    char default_output[512];
+    if (ascii_armor) {
+        snprintf(default_output, sizeof(default_output), "%s.otp.asc", input_file);
+    } else {
+        snprintf(default_output, sizeof(default_output), "%s.otp", input_file);
+    }
+    
+    // Ask for output filename with pre-filled default
+    printf("\nOutput filename [%s]: ", default_output);
+    char output_file[512];
+    if (!fgets(output_file, sizeof(output_file), stdin)) {
+        printf("Error: Failed to read input\n");
+        return 1;
+    }
+    output_file[strcspn(output_file, "\n")] = 0;
+    
+    // Use default if user just pressed Enter
+    const char* output_filename = (strlen(output_file) > 0) ? output_file : default_output;
+    
+    return encrypt_file(pad_input, input_file, output_filename, ascii_armor);
 }
 
 int handle_smart_decrypt(void) {
diff --git a/test.txt.otp b/test.txt.otp
new file mode 100644
index 0000000..4cc77c2
Binary files /dev/null and b/test.txt.otp differ