diff --git a/PBGitCommit.h b/PBGitCommit.h
index 70a6001..9a7832e 100644
--- a/PBGitCommit.h
+++ b/PBGitCommit.h
@@ -30,7 +30,7 @@
 
 - initWithRepository:(PBGitRepository *)repo andSha:(git_oid)sha;
 
-- (void)addRef:(id)ref;
+- (void)addRef:(PBGitRef *)ref;
 - (void)removeRef:(id)ref;
 
 - (NSString *)realSha;
diff --git a/PBGitCommit.m b/PBGitCommit.m
index 37dc312..dbfdbdf 100644
--- a/PBGitCommit.m
+++ b/PBGitCommit.m
@@ -94,7 +94,7 @@
 	return [PBGitTree rootForCommit: self];
 }
 
-- (void)addRef:(id)ref
+- (void)addRef:(PBGitRef *)ref
 {
 	if (!self.refs)
 		self.refs = [NSMutableArray arrayWithObject:ref];
@@ -108,8 +108,6 @@
 		return;
 
 	[self.refs removeObject:ref];
-	if ([self.refs count] == 0)
-		self.refs = NULL;
 }
 
 - (NSMutableArray *)refs
@@ -119,7 +117,7 @@
 
 - (void) setRefs:(NSMutableArray *)refs
 {
-	[[repository refs] setObject:[self realSha] forKey:[self realSha]];
+	[[repository refs] setObject:refs forKey:[self realSha]];
 }
 
 - (void)finalize
diff --git a/PBGitRevisionCell.m b/PBGitRevisionCell.m
index 83bf906..7d0d079 100644
--- a/PBGitRevisionCell.m
+++ b/PBGitRevisionCell.m
@@ -229,7 +229,7 @@
 	}
 
 
-	if ([self.objectValue refs])
+	if ([self.objectValue refs] && [[self.objectValue refs] count])
 		[self drawRefsInRect:&rect];
 
 	// Still use this superclass because of hilighting differences