diff --git a/plugin/hosts/hostsfile.go b/plugin/hosts/hostsfile.go
index f3ef2cc75..e8f3a9dd7 100644
--- a/plugin/hosts/hostsfile.go
+++ b/plugin/hosts/hostsfile.go
@@ -164,11 +164,20 @@ func (h *Hostsfile) initInline(inline []string) {
 	h.inline = h.parse(strings.NewReader(strings.Join(inline, "\n")))
 }
 
+// maxLineSize is the largest hosts file line we are willing to parse. A line
+// can legitimately be long when many names share a single address, so this is
+// well above bufio.Scanner's 64KiB default, but still bounded.
+const maxLineSize = 1024 * 1024
+
 // Parse reads the hostsfile and populates the byName and addr maps.
 func (h *Hostsfile) parse(r io.Reader) *Map {
 	hmap := newMap()
 
 	scanner := bufio.NewScanner(r)
+	// The scanner grows its buffer as needed; only raise the limit at which it
+	// gives up, otherwise a single long line aborts the scan and every entry
+	// after it is dropped.
+	scanner.Buffer(nil, maxLineSize)
 	for scanner.Scan() {
 		line := scanner.Bytes()
 		if i := bytes.Index(line, []byte{'#'}); i >= 0 {
@@ -220,6 +229,10 @@ func (h *Hostsfile) parse(r io.Reader) *Map {
 			hmap.addr[addr.String()] = append(hmap.addr[addr.String()], name)
 		}
 	}
+	if err := scanner.Err(); err != nil {
+		// Entries after the failing line have not been read.
+		log.Errorf("Failed to parse hosts file %q: %v", h.path, err)
+	}
 
 	return hmap
 }
diff --git a/plugin/hosts/hostsfile_test.go b/plugin/hosts/hostsfile_test.go
index 4d9595220..6322d9849 100644
--- a/plugin/hosts/hostsfile_test.go
+++ b/plugin/hosts/hostsfile_test.go
@@ -290,3 +290,19 @@ func TestLookupStaticHostReloadRace(t *testing.T) {
 
 	wg.Wait()
 }
+
+func TestParseLineLongerThanDefaultScanBuffer(t *testing.T) {
+	// A line longer than bufio.Scanner's default 64KiB buffer must not stop
+	// the scan: the entries that follow it still have to be parsed.
+	long := strings.Repeat("a", 70*1024)
+	h := testHostsfile("127.0.0.1 before.example.org\n" +
+		"127.0.0.2 " + long + ".example.org\n" +
+		"127.0.0.3 after.example.org\n")
+
+	if addrs := h.LookupStaticHostV4("before.example.org."); len(addrs) != 1 || addrs[0].String() != "127.0.0.1" {
+		t.Errorf("LookupStaticHostV4(before.example.org.) = %v, want [127.0.0.1]", addrs)
+	}
+	if addrs := h.LookupStaticHostV4("after.example.org."); len(addrs) != 1 || addrs[0].String() != "127.0.0.3" {
+		t.Errorf("LookupStaticHostV4(after.example.org.) = %v, want [127.0.0.3]", addrs)
+	}
+}