diff --git a/PBGitGrapher.mm b/PBGitGrapher.mm
index 790f383..b71b60d 100644
--- a/PBGitGrapher.mm
+++ b/PBGitGrapher.mm
@@ -55,6 +55,7 @@ void add_line(struct PBGitGraphLine *lines, int *nLines, int upper, int from, in
 			i++;
 			if(*it == (PBGitLane *)endLane) {
 				delete *it;
+				endLane = NULL;
 				continue;
 			}
 			// This is our commit! We should do a "merge": move the line from