diff --git a/internal/core/booking/booking.go b/internal/core/booking/booking.go
index f681aa1..0e420dd 100644
--- a/internal/core/booking/booking.go
+++ b/internal/core/booking/booking.go
@@ -107,7 +107,7 @@ func (a *Adapter) Book(member *discord.Member, guild *discord.Guild, spotName st
 	}
 
 	if endAt.Sub(startAt) > 3*time.Hour {
-		return []*reservation.Reservation{}, fmt.Errorf("reservation cannot take more than 3 hours")
+		return []*reservation.Reservation{}, errors.New("reservation cannot take more than 3 hours")
 	}
 
 	conflictingReservations, err := a.reservationRepo.SelectOverlappingReservations(context.Background(), spotName, startAt, endAt, guild.ID)
@@ -115,12 +115,20 @@ func (a *Adapter) Book(member *discord.Member, guild *discord.Guild, spotName st
 		return []*reservation.Reservation{}, fmt.Errorf("could not select overlapping reservations: %w", err)
 	}
 
+	authorsConflictingReservations, _ := collections.PoorMansFind(conflictingReservations, func(r *reservation.Reservation) bool {
+		return r.AuthorDiscordID == member.ID
+	})
+
+	if authorsConflictingReservations != nil && overbook {
+		return []*reservation.Reservation{}, errors.New("you cannot overbook yourself")
+	}
+
 	if len(conflictingReservations) > 0 {
 		switch canDo := overbook && isPotentiallyAbandonedReservation(conflictingReservations) || overbook && hasPermissions; canDo {
 		case true:
 			break
 		case false:
-			return conflictingReservations, fmt.Errorf("There are conflicting reservation which prevented booking this reservation. If you would like to overbook them, ensure you have a @Postman role, then repeat the command and set 'overbook' parameter to 'true'.")
+			return conflictingReservations, errors.New("There are conflicting reservation which prevented booking this reservation. If you would like to overbook them, ensure you have a @Postman role, then repeat the command and set 'overbook' parameter to 'true'.")
 		}
 	}
 
diff --git a/internal/core/booking/booking_test.go b/internal/core/booking/booking_test.go
index ff4d5a1..3556fdb 100644
--- a/internal/core/booking/booking_test.go
+++ b/internal/core/booking/booking_test.go
@@ -418,3 +418,46 @@ func TestBookOnMultizoneCase(t *testing.T) {
 	assert.Nil(err)
 	assert.NotNil(res)
 }
+
+func TestBookFailOnOverbookAuthorsReservation(t *testing.T) {
+	// given
+	assert := assert.New(t)
+	guild := &discord.Guild{
+		ID:   "test-id",
+		Name: "test-guild-name",
+	}
+	member := &discord.Member{
+		ID:   "test-member",
+		Nick: "test-nick",
+	}
+	startAt := time.Now()
+	endAt := startAt.Add(1 * time.Hour)
+	spotInput := &spot.Spot{
+		Name:      "test-spot",
+		ID:        1,
+		CreatedAt: time.Now(),
+	}
+	conflictingReservations := []*reservation.Reservation{
+		{
+			Author:          member.Username,
+			CreatedAt:       time.Now(),
+			StartAt:         time.Date(1, 1, 1, 16, 0, 0, 0, time.UTC),
+			EndAt:           time.Date(1, 1, 1, 17, 0, 0, 0, time.UTC),
+			SpotID:          1,
+			GuildID:         guild.ID,
+			AuthorDiscordID: member.ID,
+		},
+	}
+	spotService := new(mocks.MockSpotRepo)
+	spotService.On("SelectAllSpots", mocks.ContextMock).Return([]*spot.Spot{spotInput}, nil)
+	reservationService := new(mocks.MockReservationRepo)
+	reservationService.On("SelectOverlappingReservations", mocks.ContextMock, spotInput.Name, startAt, endAt, guild.ID).Return(conflictingReservations, nil)
+	adapter := NewAdapter(spotService, reservationService)
+
+	// when
+	res, err := adapter.Book(member, guild, spotInput.Name, startAt, endAt, true, true)
+
+	// assert
+	assert.NotNil(err)
+	assert.Empty(res)
+}
diff --git a/internal/infrastructure/bot/handlers.go b/internal/infrastructure/bot/handlers.go
index f3514cf..2ea2b85 100644
--- a/internal/infrastructure/bot/handlers.go
+++ b/internal/infrastructure/bot/handlers.go
@@ -1,6 +1,7 @@
 package bot
 
 import (
+	"errors"
 	"fmt"
 	"strings"
 	"time"
@@ -14,8 +15,10 @@ import (
 	"spot-assistant/internal/core/dto/summary"
 )
 
-// System events
-// Events that are sent by discord itself
+/*
+*
+System events that are initialized by Discord.
+*/
 
 func (b *Bot) GuildCreate(s *discordgo.Session, g *discordgo.GuildCreate) {
 	b.log.Debug("GuildCreate")
@@ -29,7 +32,7 @@ func (b *Bot) Ready(s *discordgo.Session, r *discordgo.Ready) {
 	defer b.eventHandler.OnReady(b)
 }
 
-// When a slash command is invoked, this is the entry point.
+// InteractionCreate this is the entry point when a slash command is invoked.
 func (b *Bot) InteractionCreate(s *discordgo.Session, i *discordgo.InteractionCreate) {
 	b.log.Debug("InteractionCreate")
 	tStart := time.Now()
@@ -68,7 +71,7 @@ func (b *Bot) Book(i *discordgo.InteractionCreate) error {
 	case 3:
 		break
 	default:
-		return fmt.Errorf("Book command requires 3 arguments")
+		return errors.New("book command requires 3 arguments")
 	}
 
 	startAt, err := time.Parse(stringsHelper.DC_TIME_FORMAT, i.ApplicationCommandData().Options[1].StringValue())
@@ -173,7 +176,7 @@ func (b *Bot) BookAutocomplete(i *discordgo.InteractionCreate) error {
 			return o.Focused
 		})
 	if index == -1 {
-		return fmt.Errorf("none of the options were selected for autocompletion")
+		return errors.New("none of the options were selected for autocompletion")
 	}
 
 	response, err := b.eventHandler.OnBookAutocomplete(book.BookAutocompleteRequest{
@@ -192,7 +195,7 @@ func (b *Bot) BookAutocomplete(i *discordgo.InteractionCreate) error {
 
 func (b *Bot) Unbook(i *discordgo.InteractionCreate) error {
 	if len(i.ApplicationCommandData().Options) < 1 {
-		return fmt.Errorf("you must select a reservation to unbook")
+		return errors.New("you must select a reservation to unbook")
 	}
 
 	reservationId, err := stringsHelper.StrToInt64(i.ApplicationCommandData().Options[0].StringValue())