diff --git a/src/python/m5/util/dot_writer.py b/src/python/m5/util/dot_writer.py
index f62431b015..e6de3f3219 100644
--- a/src/python/m5/util/dot_writer.py
+++ b/src/python/m5/util/dot_writer.py
@@ -338,6 +338,8 @@ def dot_create_dvfs_nodes(simNode, callgraph, domain=None):
 
 def do_dot(root, outdir, dotFilename):
     if not pydot:
+        warn("No dot file generated. " +
+             "Please install pydot to generate the dot file and pdf.")
         return
     # * use ranksep > 1.0 for for vertical separation between nodes
     # especially useful if you need to annotate edges using e.g. visio
@@ -358,6 +360,8 @@ def do_dot(root, outdir, dotFilename):
 
 def do_dvfs_dot(root, outdir, dotFilename):
     if not pydot:
+        warn("No dot file generated. " +
+             "Please install pydot to generate the dot file and pdf.")
         return
 
     # There is a chance that we are unable to resolve the clock or