diff --git a/src/main/java/org/qortal/controller/BlockMinter.java b/src/main/java/org/qortal/controller/BlockMinter.java
index f804456f..8e6f51fa 100644
--- a/src/main/java/org/qortal/controller/BlockMinter.java
+++ b/src/main/java/org/qortal/controller/BlockMinter.java
@@ -165,6 +165,14 @@ public class BlockMinter extends Thread {
 				// Do we need to build any potential new blocks?
 				List<PrivateKeyAccount> newBlocksMintingAccounts = mintingAccountsData.stream().map(accountData -> new PrivateKeyAccount(repository, accountData.getPrivateKey())).collect(Collectors.toList());
 
+				// We might need to sit the next block out, if one of our minting accounts signed the previous one
+				final byte[] previousBlockMinter = previousBlockData.getMinterPublicKey();
+				final boolean mintedLastBlock = mintingAccountsData.stream().anyMatch(mintingAccount -> Arrays.equals(mintingAccount.getPublicKey(), previousBlockMinter));
+				if (mintedLastBlock) {
+					LOGGER.trace(String.format("One of our keys signed the last block, so we won't sign the next one"));
+					continue;
+				}
+
 				for (PrivateKeyAccount mintingAccount : newBlocksMintingAccounts) {
 					// First block does the AT heavy-lifting
 					if (newBlocks.isEmpty()) {