diff --git a/pkg/detectors/slackwebhook/slackwebhook.go b/pkg/detectors/slackwebhook/slackwebhook.go
index 6a4a9d418..2f8fe6ab6 100644
--- a/pkg/detectors/slackwebhook/slackwebhook.go
+++ b/pkg/detectors/slackwebhook/slackwebhook.go
@@ -2,6 +2,7 @@ package slackwebhook
 
 import (
 	"context"
+	"fmt"
 	"io"
 	"net/http"
 	"regexp"
@@ -12,14 +13,15 @@ import (
 	"github.com/trufflesecurity/trufflehog/v3/pkg/pb/detectorspb"
 )
 
-type Scanner struct{}
+type Scanner struct {
+	client *http.Client
+}
 
 // Ensure the Scanner satisfies the interface at compile time.
 var _ detectors.Detector = (*Scanner)(nil)
 
 var (
-	client = common.SaneHttpClient()
-
+	defaultClient = common.SaneHttpClient()
 	// Make sure that your group is surrounded in boundary characters such as below to reduce false positives.
 	keyPat = regexp.MustCompile(`(https://hooks\.slack\.com/services/T[A-Z0-9]+/B[A-Z0-9]+/[A-Za-z0-9]{23,25})`)
 )
@@ -48,6 +50,12 @@ func (s Scanner) FromData(ctx context.Context, verify bool, data []byte) (result
 		}
 
 		if verify {
+
+			client := s.client
+			if client == nil {
+				client = defaultClient
+			}
+
 			payload := strings.NewReader(`{"text": ""}`)
 			req, err := http.NewRequestWithContext(ctx, "POST", resMatch, payload)
 			if err != nil {
@@ -62,9 +70,18 @@ func (s Scanner) FromData(ctx context.Context, verify bool, data []byte) (result
 					continue
 				}
 				body := string(bodyBytes)
-				if (res.StatusCode >= 200 && res.StatusCode < 300) || (res.StatusCode == 400 && (strings.Contains(body, "no_text") || strings.Contains(body, "missing_text"))) {
+
+				defer res.Body.Close()
+
+				if res.StatusCode >= 200 && res.StatusCode < 300 || (res.StatusCode == 400 && (strings.Contains(body, "no_text") || strings.Contains(body, "missing_text"))) {
 					s1.Verified = true
+				} else if res.StatusCode == 401 || res.StatusCode == 403 {
+					// The secret is determinately not verified (nothing to do)
+				} else {
+					s1.VerificationError = fmt.Errorf("unexpected HTTP response status %d", res.StatusCode)
 				}
+			} else {
+				s1.VerificationError = err
 			}
 		}
 
diff --git a/pkg/detectors/slackwebhook/slackwebhook_test.go b/pkg/detectors/slackwebhook/slackwebhook_test.go
index dd9b35f47..2d7e80a3a 100644
--- a/pkg/detectors/slackwebhook/slackwebhook_test.go
+++ b/pkg/detectors/slackwebhook/slackwebhook_test.go
@@ -6,10 +6,11 @@ package slackwebhook
 import (
 	"context"
 	"fmt"
+	"github.com/google/go-cmp/cmp"
+	"github.com/google/go-cmp/cmp/cmpopts"
 	"testing"
 	"time"
 
-	"github.com/kylelemons/godebug/pretty"
 	"github.com/trufflesecurity/trufflehog/v3/pkg/detectors"
 
 	"github.com/trufflesecurity/trufflehog/v3/pkg/common"
@@ -32,11 +33,12 @@ func TestSlackWebhook_FromChunk(t *testing.T) {
 		verify bool
 	}
 	tests := []struct {
-		name    string
-		s       Scanner
-		args    args
-		want    []detectors.Result
-		wantErr bool
+		name                string
+		s                   Scanner
+		args                args
+		want                []detectors.Result
+		wantErr             bool
+		wantVerificationErr bool
 	}{
 		{
 			name: "found, verified",
@@ -52,7 +54,8 @@ func TestSlackWebhook_FromChunk(t *testing.T) {
 					Verified:     true,
 				},
 			},
-			wantErr: false,
+			wantErr:             false,
+			wantVerificationErr: false,
 		},
 		{
 			name: "found, unverified",
@@ -68,7 +71,8 @@ func TestSlackWebhook_FromChunk(t *testing.T) {
 					Verified:     false,
 				},
 			},
-			wantErr: false,
+			wantErr:             false,
+			wantVerificationErr: false,
 		},
 		{
 			name: "not found",
@@ -78,14 +82,48 @@ func TestSlackWebhook_FromChunk(t *testing.T) {
 				data:   []byte("You cannot find the secret within"),
 				verify: true,
 			},
-			want:    nil,
-			wantErr: false,
+			want:                nil,
+			wantErr:             false,
+			wantVerificationErr: false,
+		},
+		{
+			name: "found, would be verified if not for timeout",
+			s:    Scanner{client: common.SaneHttpClientTimeOut(1 * time.Microsecond)},
+			args: args{
+				ctx:    context.Background(),
+				data:   []byte(fmt.Sprintf("You can find a slackwebhook secret %s within", secret)),
+				verify: true,
+			},
+			want: []detectors.Result{
+				{
+					DetectorType: detectorspb.DetectorType_SlackWebhook,
+					Verified:     false,
+				},
+			},
+			wantErr:             false,
+			wantVerificationErr: true,
+		},
+		{
+			name: "found, verified but unexpected api surface",
+			s:    Scanner{client: common.ConstantResponseHttpClient(404, "")},
+			args: args{
+				ctx:    context.Background(),
+				data:   []byte(fmt.Sprintf("You can find a slackwebhook secret %s within", secret)),
+				verify: true,
+			},
+			want: []detectors.Result{
+				{
+					DetectorType: detectorspb.DetectorType_SlackWebhook,
+					Verified:     false,
+				},
+			},
+			wantErr:             false,
+			wantVerificationErr: true,
 		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			s := Scanner{}
-			got, err := s.FromData(tt.args.ctx, tt.args.verify, tt.args.data)
+			got, err := tt.s.FromData(tt.args.ctx, tt.args.verify, tt.args.data)
 			if (err != nil) != tt.wantErr {
 				t.Errorf("SlackWebhook.FromData() error = %v, wantErr %v", err, tt.wantErr)
 				return
@@ -94,9 +132,12 @@ func TestSlackWebhook_FromChunk(t *testing.T) {
 				if len(got[i].Raw) == 0 {
 					t.Fatalf("no raw secret present: \n %+v", got[i])
 				}
-				got[i].Raw = nil
+				if (got[i].VerificationError != nil) != tt.wantVerificationErr {
+					t.Fatalf("wantVerificationError = %v, verification error = %v", tt.wantVerificationErr, got[i].VerificationError)
+				}
 			}
-			if diff := pretty.Compare(got, tt.want); diff != "" {
+			ignoreOpts := cmpopts.IgnoreFields(detectors.Result{}, "Raw", "VerificationError")
+			if diff := cmp.Diff(got, tt.want, ignoreOpts); diff != "" {
 				t.Errorf("SlackWebhook.FromData() %s diff: (-got +want)\n%s", tt.name, diff)
 			}
 		})