diff --git a/whisper/whisperv5/filter.go b/whisper/whisperv5/filter.go
index d571160d7f..5775462a7a 100644
--- a/whisper/whisperv5/filter.go
+++ b/whisper/whisperv5/filter.go
@@ -22,6 +22,7 @@ import (
 	"sync"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/log"
 )
 
@@ -68,6 +69,10 @@ func (fs *Filters) Install(watcher *Filter) (string, error) {
 		return "", fmt.Errorf("failed to generate unique ID")
 	}
 
+	if watcher.expectsSymmetricEncryption() {
+		watcher.SymKeyHash = crypto.Keccak256Hash(watcher.KeySym);
+	}
+
 	fs.watchers[id] = watcher
 	return id, err
 }
diff --git a/whisper/whisperv5/filter_test.go b/whisper/whisperv5/filter_test.go
index 4ce87eee22..2f3a679111 100644
--- a/whisper/whisperv5/filter_test.go
+++ b/whisper/whisperv5/filter_test.go
@@ -132,6 +132,38 @@ func TestInstallFilters(t *testing.T) {
 	}
 }
 
+func TestInstallSymKeyGeneratesHash(t *testing.T) {
+	InitSingleTest()
+
+	w := New(&Config{})
+	filters := NewFilters(w)
+	filter, _ := generateFilter(t, true)
+
+	// save the current SymKeyHash for comparison
+	initialSymKeyHash := filter.SymKeyHash
+
+	// ensure the SymKeyHash is invalid, for Install to recreate it
+	var invalid common.Hash
+	filter.SymKeyHash = invalid
+
+	_, err := filters.Install(filter)
+
+	if err != nil {
+		t.Fatalf("Error installing the filter: %v", err);
+	}
+
+	identicalBytes := true
+	for i, b := range filter.SymKeyHash {
+		if b != initialSymKeyHash[i] {
+			identicalBytes = false
+			break
+		}
+	}
+	if identicalBytes == false {
+		t.Fatalf("The filter's symmetric key hash was not properly generated by Install")
+	}
+}
+
 func TestComparePubKey(t *testing.T) {
 	InitSingleTest()