diff --git a/.tools/envs/testenv-linux.yml b/.tools/envs/testenv-linux.yml
index f80b48eb8..827c56d40 100644
--- a/.tools/envs/testenv-linux.yml
+++ b/.tools/envs/testenv-linux.yml
@@ -28,7 +28,7 @@ dependencies:
   - jinja2  # dev, tests
   - annotated-types  # dev, tests
   - pip:  # dev, tests, docs
-      - DFO-LS  # dev, tests
+      - DFO-LS>=1.5.3  # dev, tests
       - Py-BOBYQA  # dev, tests
       - fides==0.7.4  # dev, tests
       - kaleido  # dev, tests
diff --git a/.tools/envs/testenv-numpy.yml b/.tools/envs/testenv-numpy.yml
index f54e96c17..ef75ece28 100644
--- a/.tools/envs/testenv-numpy.yml
+++ b/.tools/envs/testenv-numpy.yml
@@ -26,7 +26,7 @@ dependencies:
   - jinja2  # dev, tests
   - annotated-types  # dev, tests
   - pip:  # dev, tests, docs
-      - DFO-LS  # dev, tests
+      - DFO-LS>=1.5.3  # dev, tests
       - Py-BOBYQA  # dev, tests
       - fides==0.7.4  # dev, tests
       - kaleido  # dev, tests
diff --git a/.tools/envs/testenv-others.yml b/.tools/envs/testenv-others.yml
index 0fc410f86..9b81be122 100644
--- a/.tools/envs/testenv-others.yml
+++ b/.tools/envs/testenv-others.yml
@@ -26,7 +26,7 @@ dependencies:
   - jinja2  # dev, tests
   - annotated-types  # dev, tests
   - pip:  # dev, tests, docs
-      - DFO-LS  # dev, tests
+      - DFO-LS>=1.5.3  # dev, tests
       - Py-BOBYQA  # dev, tests
       - fides==0.7.4  # dev, tests
       - kaleido  # dev, tests
diff --git a/.tools/envs/testenv-pandas.yml b/.tools/envs/testenv-pandas.yml
index 6918bafae..d7e99f2be 100644
--- a/.tools/envs/testenv-pandas.yml
+++ b/.tools/envs/testenv-pandas.yml
@@ -26,7 +26,7 @@ dependencies:
   - jinja2  # dev, tests
   - annotated-types  # dev, tests
   - pip:  # dev, tests, docs
-      - DFO-LS  # dev, tests
+      - DFO-LS>=1.5.3  # dev, tests
       - Py-BOBYQA  # dev, tests
       - fides==0.7.4  # dev, tests
       - kaleido  # dev, tests
diff --git a/docs/source/algorithms.md b/docs/source/algorithms.md
index 363ce5faf..006e25402 100644
--- a/docs/source/algorithms.md
+++ b/docs/source/algorithms.md
@@ -1083,6 +1083,8 @@ install each of them separately:
 ```{eval-rst}
 .. dropdown::  nag_dfols
 
+    *Note*: We recommend to install `DFO-LS` version 1.5.3 or higher. Versions of 1.5.0 or lower also work but the versions `1.5.1` and `1.5.2` contain bugs that can lead to errors being raised.
+
     .. code-block::
 
         "nag_dfols"
diff --git a/docs/source/installation.md b/docs/source/installation.md
index 1c4ea3ac5..912e213b6 100644
--- a/docs/source/installation.md
+++ b/docs/source/installation.md
@@ -40,6 +40,10 @@ pip install Py-BOBYQA
 pip install DFO-LS
 ```
 
+*Note*: We recommend to install `DFO-LS` version 1.5.3 or higher. Versions of 1.5.0 or
+lower also work but the versions `1.5.1` and `1.5.2` contain bugs that can lead to
+errors being raised.
+
 ```
 conda install -c conda-forge petsc4py
 ```
diff --git a/environment.yml b/environment.yml
index 562d1c9cd..a608d5540 100644
--- a/environment.yml
+++ b/environment.yml
@@ -38,7 +38,7 @@ dependencies:
   - furo  # dev, docs
   - annotated-types  # dev, tests
   - pip:  # dev, tests, docs
-      - DFO-LS  # dev, tests
+      - DFO-LS>=1.5.3  # dev, tests
       - Py-BOBYQA  # dev, tests
       - fides==0.7.4  # dev, tests
       - kaleido  # dev, tests
diff --git a/src/optimagic/optimizers/nag_optimizers.py b/src/optimagic/optimizers/nag_optimizers.py
index a83ac7900..e708b5915 100644
--- a/src/optimagic/optimizers/nag_optimizers.py
+++ b/src/optimagic/optimizers/nag_optimizers.py
@@ -630,7 +630,7 @@ def nag_dfols_internal(
         fun=res["solution_criterion"],
         success=res["success"],
         message=res["message"],
-        n_iterations=int(res["n_iterations"]),
+        n_iterations=res["n_iterations"],
         n_fun_evals=res["n_fun_evals"],
     )
     return out
@@ -857,7 +857,7 @@ def nag_pybobyqa_internal(
         fun=res["solution_criterion"],
         success=res["success"],
         message=res["message"],
-        n_iterations=int(res["n_iterations"]),
+        n_iterations=res["n_iterations"],
     )
 
     return out
@@ -890,9 +890,8 @@ def _process_nag_result(nag_result_obj, len_x):
         "diagnostic_info": nag_result_obj.diagnostic_info,
     }
     try:
-        processed["n_iterations"] = nag_result_obj.diagnostic_info["iters_total"].iloc[
-            -1
-        ]
+        n_iterations = int(nag_result_obj.diagnostic_info["iters_total"].iloc[-1])
+        processed["n_iterations"] = n_iterations
     except (KeyboardInterrupt, SystemExit):
         raise
     except Exception:
diff --git a/tests/optimagic/optimization/test_many_algorithms.py b/tests/optimagic/optimization/test_many_algorithms.py
index 52b7df33c..1882aeb08 100644
--- a/tests/optimagic/optimization/test_many_algorithms.py
+++ b/tests/optimagic/optimization/test_many_algorithms.py
@@ -86,3 +86,15 @@ def test_global_algorithms_on_sum_of_squares(algorithm):
     )
     assert res.success in [True, None]
     aaae(res.params, np.array([0.2, 0]), decimal=1)
+
+
+def test_nag_dfols_starting_at_optimum():
+    # From issue: https://github.com/optimagic-dev/optimagic/issues/538
+    params = np.zeros(2, dtype=float)
+    res = minimize(
+        fun=sos,
+        params=params,
+        algorithm="nag_dfols",
+        bounds=Bounds(-1 * np.ones_like(params), np.ones_like(params)),
+    )
+    aaae(res.params, params)