diff --git a/metropolis/node/core/mgmt/svc_logs.go b/metropolis/node/core/mgmt/svc_logs.go
index baf9d9b..9d27d63 100644
--- a/metropolis/node/core/mgmt/svc_logs.go
+++ b/metropolis/node/core/mgmt/svc_logs.go
@@ -1,6 +1,8 @@
 package mgmt
 
 import (
+	"strings"
+
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
 
@@ -19,6 +21,42 @@
 	LogTree *logtree.LogTree
 }
 
+// sanitizedEntries returns a deep copy of the given log entries, but replaces
+// all invalid UTF-8 characters with "<INVALID>".
+func sanitizedEntries(entries []*cpb.LogEntry) []*cpb.LogEntry {
+	res := make([]*cpb.LogEntry, len(entries))
+	for i, entry := range entries {
+		res[i] = &cpb.LogEntry{
+			Dn:   entry.Dn,
+			Kind: nil,
+		}
+		switch k := entry.Kind.(type) {
+		case *cpb.LogEntry_Leveled_:
+			leveled := &cpb.LogEntry_Leveled_{
+				Leveled: &cpb.LogEntry_Leveled{
+					Lines:     make([]string, len(k.Leveled.Lines)),
+					Timestamp: k.Leveled.Timestamp,
+					Severity:  k.Leveled.Severity,
+					Location:  k.Leveled.Location,
+				},
+			}
+			for j, line := range k.Leveled.Lines {
+				leveled.Leveled.Lines[j] = strings.ToValidUTF8(line, "<INVALID>")
+			}
+			res[i].Kind = leveled
+
+		case *cpb.LogEntry_Raw_:
+			res[i].Kind = &cpb.LogEntry_Raw_{
+				Raw: &cpb.LogEntry_Raw{
+					Data:           strings.ToValidUTF8(k.Raw.Data, "<INVALID>"),
+					OriginalLength: k.Raw.OriginalLength,
+				},
+			}
+		}
+	}
+	return res
+}
+
 func (s *LogService) Logs(req *api.GetLogsRequest, srv api.NodeManagement_LogsServer) error {
 	if len(req.Filters) > logFilterMax {
 		return status.Errorf(codes.InvalidArgument, "requested %d filters, maximum permitted is %d", len(req.Filters), logFilterMax)
@@ -113,7 +151,7 @@
 
 		if len(chunk) >= maxChunkSize {
 			err := srv.Send(&api.GetLogsResponse{
-				BacklogEntries: chunk,
+				BacklogEntries: sanitizedEntries(chunk),
 			})
 			if err != nil {
 				return err
@@ -125,7 +163,7 @@
 	// Send last chunk of backlog, if present..
 	if len(chunk) > 0 {
 		err := srv.Send(&api.GetLogsResponse{
-			BacklogEntries: chunk,
+			BacklogEntries: sanitizedEntries(chunk),
 		})
 		if err != nil {
 			return err
diff --git a/metropolis/node/core/mgmt/svc_logs_test.go b/metropolis/node/core/mgmt/svc_logs_test.go
index d5825ad..9517600 100644
--- a/metropolis/node/core/mgmt/svc_logs_test.go
+++ b/metropolis/node/core/mgmt/svc_logs_test.go
@@ -123,6 +123,7 @@
 	s.LogTree.MustLeveledFor("main.roleserver.controlplane").Infof("Starting control plane...")
 	s.LogTree.MustLeveledFor("main.roleserver.kubernetes").Infof("Kubernetes version: 1.21.37")
 	s.LogTree.MustLeveledFor("main.roleserver.controlplane").Infof("Starting etcd...")
+	s.LogTree.MustLeveledFor("main.weirdo").Infof("Here comes some invalid utf-8: a\xc5z")
 
 	mkReq := func(dn string, backlog int64) *api.GetLogsRequest {
 		var backlogMode api.GetLogsRequest_BacklogMode
@@ -175,7 +176,6 @@
 			req:  mkReq("main.roleserver.kubernetes", 0),
 			want: nil,
 		},
-
 		{
 			// Test recursion with backlog.
 			req: mkRecursive(mkReq("main.roleserver", 2)),
@@ -184,6 +184,13 @@
 				mkLeveledEntry("main.roleserver.controlplane", "i", "Starting etcd..."),
 			},
 		},
+		{
+			// Test invalid utf-8 in log data
+			req: mkReq("main.weirdo", 1),
+			want: []*cpb.LogEntry{
+				mkLeveledEntry("main.weirdo", "i", "Here comes some invalid utf-8: a<INVALID>z"),
+			},
+		},
 	} {
 		srv, err := mgmt.Logs(ctx, te.req)
 		if err != nil {