diff --git a/src/main/java/org/qortal/transaction/CancelGroupBanTransaction.java b/src/main/java/org/qortal/transaction/CancelGroupBanTransaction.java
index a9577bc5..f3511ded 100644
--- a/src/main/java/org/qortal/transaction/CancelGroupBanTransaction.java
+++ b/src/main/java/org/qortal/transaction/CancelGroupBanTransaction.java
@@ -70,6 +70,10 @@ public class CancelGroupBanTransaction extends Transaction {
 		if (!this.repository.getGroupRepository().adminExists(groupId, admin.getAddress()))
 			return ValidationResult.NOT_GROUP_ADMIN;
 
+		// Can't unban if not group's current owner
+		if (!admin.getAddress().equals(groupData.getOwner()))
+			return ValidationResult.INVALID_GROUP_OWNER;
+
 		Account member = getMember();
 
 		// Check ban actually exists
diff --git a/src/main/java/org/qortal/transaction/GroupBanTransaction.java b/src/main/java/org/qortal/transaction/GroupBanTransaction.java
index 27c00d5c..1716d206 100644
--- a/src/main/java/org/qortal/transaction/GroupBanTransaction.java
+++ b/src/main/java/org/qortal/transaction/GroupBanTransaction.java
@@ -70,6 +70,10 @@ public class GroupBanTransaction extends Transaction {
 		if (!this.repository.getGroupRepository().adminExists(groupId, admin.getAddress()))
 			return ValidationResult.NOT_GROUP_ADMIN;
 
+		// Can't ban if not group's current owner
+		if (!admin.getAddress().equals(groupData.getOwner()))
+			return ValidationResult.INVALID_GROUP_OWNER;
+
 		Account offender = getOffender();
 
 		// Can't ban group owner
diff --git a/src/main/java/org/qortal/transaction/GroupKickTransaction.java b/src/main/java/org/qortal/transaction/GroupKickTransaction.java
index d67f3d15..3c426039 100644
--- a/src/main/java/org/qortal/transaction/GroupKickTransaction.java
+++ b/src/main/java/org/qortal/transaction/GroupKickTransaction.java
@@ -82,6 +82,10 @@ public class GroupKickTransaction extends Transaction {
 		if (!admin.getAddress().equals(groupData.getOwner()) && groupRepository.adminExists(groupId, member.getAddress()))
 			return ValidationResult.INVALID_GROUP_OWNER;
 
+		// Can't kick if not group's current owner
+		if (!admin.getAddress().equals(groupData.getOwner()))
+			return ValidationResult.INVALID_GROUP_OWNER;
+
 		// Check creator has enough funds
 		if (admin.getConfirmedBalance(Asset.QORT) < this.groupKickTransactionData.getFee())
 			return ValidationResult.NO_BALANCE;
diff --git a/src/main/java/org/qortal/transaction/UpdateGroupTransaction.java b/src/main/java/org/qortal/transaction/UpdateGroupTransaction.java
index a2546c69..b61594bd 100644
--- a/src/main/java/org/qortal/transaction/UpdateGroupTransaction.java
+++ b/src/main/java/org/qortal/transaction/UpdateGroupTransaction.java
@@ -83,6 +83,10 @@ public class UpdateGroupTransaction extends Transaction {
 
 		Account owner = getOwner();
 
+		// Check creator is group's current owner
+		if (!owner.getAddress().equals(groupData.getOwner()))
+			return ValidationResult.INVALID_GROUP_OWNER;
+
 		// Check creator has enough funds
 		if (owner.getConfirmedBalance(Asset.QORT) < this.updateGroupTransactionData.getFee())
 			return ValidationResult.NO_BALANCE;