diff --git a/RELEASES.md b/RELEASES.md
index d9bd898f7..357f9cd5a 100644
--- a/RELEASES.md
+++ b/RELEASES.md
@@ -7,6 +7,7 @@
 - Added feature `grad=last_step` for `ot.solvers.solve` (PR #693)
 - Automatic PR labeling and release file update check (PR #704)
 - Reorganize sub-module `ot/lp/__init__.py` into separate files (PR #714)
+- Fix warning raise when import the library (PR #716)
 - Implement projected gradient descent solvers for entropic partial FGW (PR #702)
 - Fix documentation in the module `ot.gaussian` (PR #718)
 - Refactored `ot.bregman._convolutional` to improve readability (PR #709)
diff --git a/ot/unbalanced/_lbfgs.py b/ot/unbalanced/_lbfgs.py
index 6ec173ad8..c4de87474 100644
--- a/ot/unbalanced/_lbfgs.py
+++ b/ot/unbalanced/_lbfgs.py
@@ -18,7 +18,7 @@
 
 
 def _get_loss_unbalanced(a, b, c, M, reg, reg_m1, reg_m2, reg_div="kl", regm_div="kl"):
-    """
+    r"""
     Return loss function for the L-BFGS-B solver
 
     .. note:: This function will be fed into scipy.optimize, so all input arrays must be Numpy arrays.