diff --git a/test/prsim_plot.py b/test/prsim_plot.py
index 4ca78a9..525dde8 100755
--- a/test/prsim_plot.py
+++ b/test/prsim_plot.py
@@ -159,7 +159,14 @@ Use -exclude='regex' to specify signals to exclude (or -ex).""")
 			plt.arrow(t0, s1, 0, s0-s1 + 0.2*np.sign(s0-s1), head_width = 0, width = 0.2, ec = "none", lw = 0, fc = "black", length_includes_head = True)
 			plt.scatter((t0),(s0), c = "black", s = 30)
 	
-	file_out_path = file_path.replace(".out",".pdf")
+
+	output_type =  ".pdf"
+	for arg in argv:
+		if arg == "-png": output_type = ".png"
+
+	file_out_path = file_path.replace(".out",output_type)
+
+
 	plt.savefig(file_out_path, bbox_inches = "tight")