diff --git a/api_handler.go b/api_handler.go
index 4f2c119f..291b1ee2 100644
--- a/api_handler.go
+++ b/api_handler.go
@@ -121,7 +121,7 @@ func (a *jobCancelEndpoint) Execute(ctx context.Context, req *jobCancelRequest)
 				if errors.Is(err, river.ErrNotFound) {
 					return nil, apierror.NewNotFoundJob(jobID)
 				}
-				return nil, fmt.Errorf("error canceling jobs: %w", err)
+				return nil, err
 			}
 			updatedJobs[jobID] = job
 		}
diff --git a/go.mod b/go.mod
index ba8d8788..e5e5b0d1 100644
--- a/go.mod
+++ b/go.mod
@@ -3,6 +3,7 @@ module github.com/riverqueue/riverui
 go 1.22
 
 require (
+	github.com/jackc/pgerrcode v0.0.0-20240316143900-6e2875d9b438
 	github.com/jackc/pgx/v5 v5.6.0
 	github.com/joho/godotenv v1.5.1
 	github.com/riverqueue/river v0.7.0
diff --git a/go.sum b/go.sum
index 422b8837..9f7f7692 100644
--- a/go.sum
+++ b/go.sum
@@ -5,8 +5,8 @@ github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
 github.com/google/go-cmp v0.5.9/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
 github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
-github.com/jackc/pgerrcode v0.0.0-20220416144525-469b46aa5efa h1:s+4MhCQ6YrzisK6hFJUX53drDT4UsSW3DEhKn0ifuHw=
-github.com/jackc/pgerrcode v0.0.0-20220416144525-469b46aa5efa/go.mod h1:a/s9Lp5W7n/DD0VrVoyJ00FbP2ytTPDVOivvn2bMlds=
+github.com/jackc/pgerrcode v0.0.0-20240316143900-6e2875d9b438 h1:Dj0L5fhJ9F82ZJyVOmBx6msDp/kfd1t9GRfny/mfJA0=
+github.com/jackc/pgerrcode v0.0.0-20240316143900-6e2875d9b438/go.mod h1:a/s9Lp5W7n/DD0VrVoyJ00FbP2ytTPDVOivvn2bMlds=
 github.com/jackc/pgpassfile v1.0.0 h1:/6Hmqy13Ss2zCq62VdNG8tM1wchn8zjSGOBJ6icpsIM=
 github.com/jackc/pgpassfile v1.0.0/go.mod h1:CEx0iS5ambNFdcRtxPj5JhEz+xB6uRky5eyVu/W2HEg=
 github.com/jackc/pgservicefile v0.0.0-20231201235250-de7065d80cb9 h1:L0QtFUgDarD7Fpv9jeVMgy/+Ec0mtnmYuImjTz6dtDA=
diff --git a/internal/apiendpoint/api_endpoint.go b/internal/apiendpoint/api_endpoint.go
index 9bbe4e3e..5de0914c 100644
--- a/internal/apiendpoint/api_endpoint.go
+++ b/internal/apiendpoint/api_endpoint.go
@@ -12,6 +12,9 @@ import (
 	"net/http"
 	"time"
 
+	"github.com/jackc/pgerrcode"
+	"github.com/jackc/pgx/v5/pgconn"
+
 	"github.com/riverqueue/riverui/internal/apierror"
 )
 
@@ -139,6 +142,18 @@ func executeAPIEndpoint[TReq any, TResp any](w http.ResponseWriter, r *http.Requ
 		return nil
 	}()
 	if err != nil {
+		// Convert certain types of Postgres errors into something more
+		// user-friendly than an internal server error.
+		var pgErr *pgconn.PgError
+		if errors.As(err, &pgErr) {
+			if pgErr.Code == pgerrcode.InsufficientPrivilege {
+				err = apierror.WithInternalError(
+					apierror.NewBadRequest("Insufficient database privilege to perform this operation."),
+					err,
+				)
+			}
+		}
+
 		var apiErr apierror.Interface
 		if errors.As(err, &apiErr) {
 			logAttrs := []any{
diff --git a/internal/apiendpoint/api_endpoint_test.go b/internal/apiendpoint/api_endpoint_test.go
index 287bd180..24ed15bf 100644
--- a/internal/apiendpoint/api_endpoint_test.go
+++ b/internal/apiendpoint/api_endpoint_test.go
@@ -5,11 +5,14 @@ import (
 	"context"
 	"encoding/json"
 	"errors"
+	"fmt"
 	"net/http"
 	"net/http/httptest"
 	"testing"
 	"time"
 
+	"github.com/jackc/pgerrcode"
+	"github.com/jackc/pgx/v5/pgconn"
 	"github.com/stretchr/testify/require"
 
 	"github.com/riverqueue/riverui/internal/apierror"
@@ -99,6 +102,18 @@ func TestMountAndServe(t *testing.T) {
 		requireStatusAndJSONResponse(t, http.StatusBadRequest, &apierror.APIError{Message: "Missing message value."}, bundle.recorder)
 	})
 
+	t.Run("InterpretedPostgresError", func(t *testing.T) {
+		t.Parallel()
+
+		mux, bundle := setup(t)
+
+		req := httptest.NewRequest(http.MethodPost, "/api/post-endpoint",
+			bytes.NewBuffer(mustMarshalJSON(t, &postRequest{MakePostgresError: true})))
+		mux.ServeHTTP(bundle.recorder, req)
+
+		requireStatusAndJSONResponse(t, http.StatusBadRequest, &apierror.APIError{Message: "Insufficient database privilege to perform this operation."}, bundle.recorder)
+	})
+
 	t.Run("Timeout", func(t *testing.T) {
 		t.Parallel()
 
@@ -219,6 +234,7 @@ func (*postEndpoint) Meta() *EndpointMeta {
 
 type postRequest struct {
 	MakeInternalError bool   `json:"make_internal_error"`
+	MakePostgresError bool   `json:"make_postgres_error"`
 	Message           string `json:"message"`
 }
 
@@ -231,6 +247,11 @@ func (a *postEndpoint) Execute(_ context.Context, req *postRequest) (*postRespon
 		return nil, errors.New("an internal error occurred")
 	}
 
+	if req.MakePostgresError {
+		// Wrap the error to make it more realistic.
+		return nil, fmt.Errorf("error runnning Postgres query: %w", &pgconn.PgError{Code: pgerrcode.InsufficientPrivilege})
+	}
+
 	if req.Message == "" {
 		return nil, apierror.NewBadRequest("Missing message value.")
 	}