diff --git a/compiler/characterizer/stimuli.py b/compiler/characterizer/stimuli.py
index e4d81d30..0c6fd7d8 100644
--- a/compiler/characterizer/stimuli.py
+++ b/compiler/characterizer/stimuli.py
@@ -272,7 +272,10 @@ def write_control(stim_file, end_time):
 def write_include(stim_file, models):
     """Writes include statements, inputs are lists of model files"""
     for item in list(models):
-        stim_file.write(".include \"{0}\"\n\n".format(item))
+        if os.path.isfile(item):
+            stim_file.write(".include \"{0}\"\n\n".format(item))
+        else:
+            debug.error("Could not find spice model: {0}".format(item))
 
 
 def write_supply(stim_file):