diff --git a/cmd/frostfs-cli/modules/object/range.go b/cmd/frostfs-cli/modules/object/range.go
index be4fee4cf..6ec508ae2 100644
--- a/cmd/frostfs-cli/modules/object/range.go
+++ b/cmd/frostfs-cli/modules/object/range.go
@@ -154,7 +154,7 @@ func printECInfoErr(cmd *cobra.Command, err error) bool {
 	if ok {
 		toJSON, _ := cmd.Flags().GetBool(commonflags.JSON)
 		toProto, _ := cmd.Flags().GetBool("proto")
-		if !(toJSON || toProto) {
+		if !toJSON && !toProto {
 			cmd.PrintErrln("Object is erasure-encoded, ec information received.")
 		}
 		printECInfo(cmd, errECInfo.ECInfo())
diff --git a/pkg/morph/event/notary_preparator.go b/pkg/morph/event/notary_preparator.go
index 40f5984a9..b11973646 100644
--- a/pkg/morph/event/notary_preparator.go
+++ b/pkg/morph/event/notary_preparator.go
@@ -199,8 +199,8 @@ func (p Preparator) validateNotaryRequest(nr *payload.P2PNotaryRequest) error {
 	// neo-go API)
 	//
 	// this check prevents notary flow recursion
-	if !(len(nr.MainTransaction.Scripts[1].InvocationScript) == 0 ||
-		bytes.Equal(nr.MainTransaction.Scripts[1].InvocationScript, p.dummyInvocationScript)) { // compatibility with old version
+	if len(nr.MainTransaction.Scripts[1].InvocationScript) != 0 &&
+		!bytes.Equal(nr.MainTransaction.Scripts[1].InvocationScript, p.dummyInvocationScript) { // compatibility with old version
 		return ErrTXAlreadyHandled
 	}
 
@@ -364,8 +364,8 @@ func (p Preparator) validateWitnesses(w []transaction.Witness, alphaKeys keys.Pu
 
 	// the last one must be a placeholder for notary contract witness
 	last := len(w) - 1
-	if !(len(w[last].InvocationScript) == 0 || // https://github.com/nspcc-dev/neo-go/pull/2981
-		bytes.Equal(w[last].InvocationScript, p.dummyInvocationScript)) || // compatibility with old version
+	if (len(w[last].InvocationScript) != 0 && // https://github.com/nspcc-dev/neo-go/pull/2981
+		!bytes.Equal(w[last].InvocationScript, p.dummyInvocationScript)) || // compatibility with old version
 		len(w[last].VerificationScript) != 0 {
 		return errIncorrectNotaryPlaceholder
 	}