diff --git a/models/common.py b/models/common.py
index cfa688ba9..a1269c5f3 100644
--- a/models/common.py
+++ b/models/common.py
@@ -477,8 +477,7 @@ class DetectMultiBackend(nn.Module):
                 self.bindings['images'] = self.bindings['images']._replace(shape=im.shape)
                 self.bindings['output'].data.resize_(tuple(self.context.get_binding_shape(i_out)))
             s = self.bindings['images'].shape
-            assert im.shape == s, f"image shape {im.shape} " + \
-                                  f"exceeds model max shape {s}" if self.dynamic else f"does not match model shape {s}"
+            assert im.shape == s, f"input size {im.shape} {'>' if self.dynamic else 'not equal to'} max model size {s}"
             self.binding_addrs['images'] = int(im.data_ptr())
             self.context.execute_v2(list(self.binding_addrs.values()))
             y = self.bindings['output'].data