diff --git a/src/mermaidAPI.js b/src/mermaidAPI.js
index e6e6c1fca..7b5e0293f 100644
--- a/src/mermaidAPI.js
+++ b/src/mermaidAPI.js
@@ -81,6 +81,7 @@ function parse(text) {
   log.debug('Type ' + graphType);
   switch (graphType) {
     case 'gitGraph':
+      gitGraphAst.clear();
       parser = gitGraphParser;
       parser.parser.yy = gitGraphAst;
       break;