diff --git a/text2image.py b/text2image.py
index 4ddeec3..ea66b91 100644
--- a/text2image.py
+++ b/text2image.py
@@ -1,3 +1,4 @@
+from datetime import datetime
 from tensorflow import keras
 from stable_diffusion_tf.stable_diffusion import Text2Image
 import argparse
@@ -17,7 +18,7 @@
     "--output",
     type=str,
     nargs="?",
-    default="output",
+    default=None,
     help="where to save the output image",
 )
 
@@ -68,6 +69,7 @@
 
 args = parser.parse_args()
 
+
 if args.mp:
     print("Using mixed precision.")
     keras.mixed_precision.set_global_policy("mixed_float16")
@@ -82,12 +84,31 @@
     seed=args.seed,
 )
 
-fname = args.output
+if not args.output:
+    # When not providing an output filename, create something using
+    # the prompt and a timestamp to prevent overwriting of existing files
+    # Get a timestamp without  microseconds, and replace colons with dots
+    timestamp = datetime.now().isoformat("T").split(".")[0].replace(":", ".")
+
+    # Create a 'slug' with only valid alphanumeric characters and spaces to
+    # prevent filename issues
+    slug_prompt = "".join(c for c in args.prompt if (c.isalnum() or c in "_- "))
+
+    # Trim the length to 100 characters to prevent issues with maximum pathlength
+    slug_prompt = slug_prompt[0:100]
+
+    # And create the final filename
+    fname = f"{timestamp} - {slug_prompt}"
+else:
+    # Output filename provided, use that
+    fname = args.output
+
 if fname.endswith(".png"):
     fname = fname[:-4]
+
 if args.batch_size == 1:
-    Image.fromarray(img[0]).save(args.output + ".png")
-    print(f"saved at {args.output}.png")
+    Image.fromarray(img[0]).save(f"{fname}.png")
+    print(f"saved at {fname}.png")
 else:
     for i in range(args.batch_size):
         fname_i = f"{fname}_{i}.png"