diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/api/CloneCommand.java b/org.eclipse.jgit/src/org/eclipse/jgit/api/CloneCommand.java
index 1f979a938..87c95ec83 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/api/CloneCommand.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/api/CloneCommand.java
@@ -318,7 +318,9 @@ private FetchResult fetch(Repository clonedRepo, URIish u)
 		if (depth != null) {
 			command.setDepth(depth.intValue());
 		}
-		command.setShallowSince(shallowSince);
+		if (shallowSince != null) {
+			command.setShallowSince(shallowSince);
+		}
 		command.setShallowExcludes(shallowExcludes);
 		configure(command);
 
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/api/FetchCommand.java b/org.eclipse.jgit/src/org/eclipse/jgit/api/FetchCommand.java
index 84bee3620..e7a8be043 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/api/FetchCommand.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/api/FetchCommand.java
@@ -227,7 +227,9 @@ public FetchResult call() throws GitAPIException, InvalidRemoteException,
 				}
 				transport.setDepth(Constants.INFINITE_DEPTH);
 			}
-			transport.setDeepenSince(deepenSince);
+			if (deepenSince != null) {
+				transport.setDeepenSince(deepenSince);
+			}
 			transport.setDeepenNots(shallowExcludes);
 			configure(transport);
 			FetchResult result = transport.fetch(monitor,