diff --git a/InitMate.sh b/InitMate.sh
index 996d28d..a7b0740 100644
--- a/InitMate.sh
+++ b/InitMate.sh
@@ -197,8 +197,15 @@ add_users() {
             echo "$USERNAME:$PASSWORD" | chpasswd
 
             if prompt_yes_no "Do you want to grant sudo access to $USERNAME?"; then
-                usermod -aG sudo "$USERNAME"
-                log "$USERNAME has been granted sudo access."
+                if getent group sudo >/dev/null; then
+                    usermod -aG sudo "$USERNAME"
+                    log "$USERNAME has been granted sudo access via sudo group."
+                elif getent group wheel >/dev/null; then
+                    usermod -aG wheel "$USERNAME"
+                    log "$USERNAME has been granted sudo access via wheel group."
+                else
+                    log "Neither sudo nor wheel group exists. Cannot grant sudo access to $USERNAME."
+                fi
             fi
 
             if prompt_yes_no "Do you want to add a public key for $USERNAME?"; then