diff --git a/export.py b/export.py
index d4191d80b410..7ec937c129d5 100644
--- a/export.py
+++ b/export.py
@@ -478,6 +478,7 @@ def run(
     device = select_device(device)
     if half:
         assert device.type != 'cpu' or coreml or xml, '--half only compatible with GPU export, i.e. use --device 0'
+        assert not dynamic, '--half not compatible with --dynamic, i.e. use either --half or --dynamic but not both'
     model = attempt_load(weights, map_location=device, inplace=True, fuse=True)  # load FP32 model
     nc, names = model.nc, model.names  # number of classes, class names