diff --git a/core/src/main/java/org/bitcoinj/core/Block.java b/core/src/main/java/org/bitcoinj/core/Block.java
index 86ae61b9a..002c17b9b 100644
--- a/core/src/main/java/org/bitcoinj/core/Block.java
+++ b/core/src/main/java/org/bitcoinj/core/Block.java
@@ -498,6 +498,7 @@ public class Block extends Message {
      * <p>This can loop forever if a solution cannot be found solely by incrementing nonce. It doesn't change
      * extraNonce.</p>
      */
+    @VisibleForTesting
     public void solve() {
         while (true) {
             try {
@@ -773,6 +774,7 @@ public class Block extends Message {
     }
 
     /** Exists only for unit testing. */
+    @VisibleForTesting
     void setMerkleRoot(Sha256Hash value) {
         unCacheHeader();
         merkleRoot = value;
@@ -823,6 +825,7 @@ public class Block extends Message {
         return prevBlockHash;
     }
 
+    @VisibleForTesting
     void setPrevBlockHash(Sha256Hash prevBlockHash) {
         unCacheHeader();
         this.prevBlockHash = prevBlockHash;
@@ -844,6 +847,7 @@ public class Block extends Message {
         return new Date(getTimeSeconds()*1000);
     }
 
+    @VisibleForTesting
     public void setTime(long time) {
         unCacheHeader();
         this.time = time;
@@ -864,6 +868,7 @@ public class Block extends Message {
     }
 
     /** Sets the difficulty target in compact form. */
+    @VisibleForTesting
     public void setDifficultyTarget(long compactForm) {
         unCacheHeader();
         this.difficultyTarget = compactForm;
@@ -879,6 +884,7 @@ public class Block extends Message {
     }
 
     /** Sets the nonce and clears any cached data. */
+    @VisibleForTesting
     public void setNonce(long nonce) {
         unCacheHeader();
         this.nonce = nonce;
@@ -947,6 +953,7 @@ public class Block extends Message {
      * 
      * @param height block height, if known, or -1 otherwise.
      */
+    @VisibleForTesting
     Block createNextBlock(@Nullable final Address to, final long version,
                           @Nullable TransactionOutPoint prevOut, final long time,
                           final byte[] pubKey, final Coin coinbaseValue,