diff --git a/core/src/main/java/com/google/bitcoin/core/Utils.java b/core/src/main/java/com/google/bitcoin/core/Utils.java
index e8adaa24..4183639e 100644
--- a/core/src/main/java/com/google/bitcoin/core/Utils.java
+++ b/core/src/main/java/com/google/bitcoin/core/Utils.java
@@ -510,8 +510,8 @@ public class Utils {
     /**
      * Sets the mock clock to the given time (in seconds).
      */
-    public static void setMockClock(long mockClock) {
-        mockTime = new Date(mockClock * 1000);
+    public static void setMockClock(long mockClockSeconds) {
+        mockTime = new Date(mockClockSeconds * 1000);
     }
 
     /**
diff --git a/core/src/test/java/com/google/bitcoin/wallet/BasicKeyChainTest.java b/core/src/test/java/com/google/bitcoin/wallet/BasicKeyChainTest.java
index 3ed0692d..90637a3e 100644
--- a/core/src/test/java/com/google/bitcoin/wallet/BasicKeyChainTest.java
+++ b/core/src/test/java/com/google/bitcoin/wallet/BasicKeyChainTest.java
@@ -61,7 +61,7 @@ public class BasicKeyChainTest {
     @Test
     public void importKeys() {
         long now = Utils.currentTimeSeconds();
-        Utils.rollMockClock(0);
+        Utils.setMockClock(now);
         final ECKey key1 = new ECKey();
         Utils.rollMockClock(86400);
         final ECKey key2 = new ECKey();
@@ -185,7 +185,7 @@ public class BasicKeyChainTest {
 
     @Test
     public void serializationUnencrypted() throws UnreadableWalletException {
-        Utils.rollMockClock(0);
+        Utils.setMockClock();
         Date now = Utils.now();
         final ECKey key1 = new ECKey();
         Utils.rollMockClock(5000);
diff --git a/core/src/test/java/com/google/bitcoin/wallet/KeyChainGroupTest.java b/core/src/test/java/com/google/bitcoin/wallet/KeyChainGroupTest.java
index cd72ffbf..56f56b77 100644
--- a/core/src/test/java/com/google/bitcoin/wallet/KeyChainGroupTest.java
+++ b/core/src/test/java/com/google/bitcoin/wallet/KeyChainGroupTest.java
@@ -45,7 +45,7 @@ public class KeyChainGroupTest {
 
     public KeyChainGroupTest() {
         BriefLogFormatter.init();
-        Utils.rollMockClock(0);
+        Utils.setMockClock();
         group = new KeyChainGroup();
         group.setLookaheadSize(LOOKAHEAD_SIZE);   // Don't want slow tests.
         group.getActiveKeyChain();  // Force create a chain.