diff --git a/x/fswap/keeper/keys.go b/x/fswap/keeper/keys.go
index 04e36660f8..e9a4652926 100644
--- a/x/fswap/keeper/keys.go
+++ b/x/fswap/keeper/keys.go
@@ -8,12 +8,29 @@ var (
 
 // swapKey key(prefix + fromDenom + toDenom)
 func swapKey(fromDenom, toDenom string) []byte {
-	key := append(swapPrefix, fromDenom...)
-	return append(key, toDenom...)
+	denoms := combineDenoms(fromDenom, toDenom)
+	return append(swapPrefix, denoms...)
 }
 
-// swappedKey key(prefix + fromDenom + toDenom)
+// swappedKey key(prefix + (lengthPrefixed+)fromDenom + (lengthPrefixed+)toDenom)
 func swappedKey(fromDenom, toDenom string) []byte {
-	key := append(swappedKeyPrefix, fromDenom...)
-	return append(key, toDenom...)
+	denoms := combineDenoms(fromDenom, toDenom)
+	return append(swappedKeyPrefix, denoms...)
+}
+
+func combineDenoms(fromDenom, toDenom string) []byte {
+	lengthPrefixedFromDenom := lengthPrefix([]byte(fromDenom))
+	lengthPrefixedToDenom := lengthPrefix([]byte(toDenom))
+	return append(lengthPrefixedFromDenom, lengthPrefixedToDenom...)
+}
+
+// lengthPrefix prefixes the address bytes with its length, this is used
+// for example for variable-length components in store keys.
+func lengthPrefix(bz []byte) []byte {
+	bzLen := len(bz)
+	if bzLen == 0 {
+		return bz
+	}
+
+	return append([]byte{byte(bzLen)}, bz...)
 }
diff --git a/x/fswap/keeper/keys_test.go b/x/fswap/keeper/keys_test.go
new file mode 100644
index 0000000000..9e814e418c
--- /dev/null
+++ b/x/fswap/keeper/keys_test.go
@@ -0,0 +1,53 @@
+package keeper
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestSwapKey(t *testing.T) {
+	tests := []struct {
+		name        string
+		fromDenom   string
+		toDenom     string
+		expectedKey []byte
+	}{
+		{
+			name:        "swapKey",
+			fromDenom:   "cony",
+			toDenom:     "peb",
+			expectedKey: []byte{0x1, 0x4, 0x63, 0x6f, 0x6e, 0x79, 0x3, 0x70, 0x65, 0x62},
+			//expectedKey: append(swapPrefix, append(append([]byte{byte(len("cony"))}, []byte("cony")...), append([]byte{byte(len("peb"))}, []byte("peb")...)...)...),
+		},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			actualKey := swapKey(tc.fromDenom, tc.toDenom)
+			require.Equal(t, tc.expectedKey, actualKey)
+		})
+	}
+}
+
+func TestSwappedKey(t *testing.T) {
+	tests := []struct {
+		name        string
+		fromDenom   string
+		toDenom     string
+		expectedKey []byte
+	}{
+		{
+			name:        "swappedKey",
+			fromDenom:   "cony",
+			toDenom:     "peb",
+			expectedKey: []byte{0x3, 0x4, 0x63, 0x6f, 0x6e, 0x79, 0x3, 0x70, 0x65, 0x62},
+			//expectedKey: append(swappedKeyPrefix, append(append([]byte{byte(len("cony"))}, []byte("cony")...), append([]byte{byte(len("peb"))}, []byte("peb")...)...)...),
+		},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			actualKey := swappedKey(tc.fromDenom, tc.toDenom)
+			require.Equal(t, tc.expectedKey, actualKey)
+		})
+	}
+}