diff --git a/cfn_clean/__init__.py b/cfn_clean/__init__.py
index 782002b..3fdb6d4 100644
--- a/cfn_clean/__init__.py
+++ b/cfn_clean/__init__.py
@@ -53,6 +53,13 @@ def convert_join(value):
                 new_parts.append("${{{}}}".format(".".join(params)))
             else:
                 for key, val in args.items():
+                    # we want to bail if a conditional can evaluate to AWS::NoValue
+                    if isinstance(val, dict):
+                        if "Fn::If" in val and "AWS::NoValue" in val["Fn::If"]:
+                            return {
+                                "Fn::Join": value,
+                            }
+
                     if val == part:
                         param_name = key
                         break

using clean produces invalid template
we are using `new_template = to_yaml( to_json( orig_template ) )` to cleanup the yaml we are producing with jinja2

`clean_up=False` we see
```
  PublicSubnetIds:
    Description: The public subnetids
    Condition: HasPublicSubnet1AZ1
    Value:
      Fn::Join:
        - ','
        -
          - Fn::If:
            - HasPublicSubnet1AZ1
            - !Ref PublicSubnet1AZ1
            - !Ref AWS::NoValue
          - Fn::If:
            - HasPublicSubnet1AZ2
            - !Ref PublicSubnet1AZ2
            - !Ref AWS::NoValue
          - Fn::If:
            - HasPublicSubnet1AZ3
            - !Ref PublicSubnet1AZ3
            - !Ref AWS::NoValue
    Export:
      Name: !Sub vpc-${Environment}-PublicSubnetIds
```
but with `clean_up=True` we get
```
  PublicSubnetIds:
    Description: The public subnetids
    Condition: HasPublicSubnet1AZ1
    Value: !Sub
      - ${Param1},${Param2},${Param3}
      - Param1: !If
          - HasPublicSubnet1AZ1
          - !Ref 'PublicSubnet1AZ1'
          - !Ref 'AWS::NoValue'
        Param2: !If
          - HasPublicSubnet1AZ2
          - !Ref 'PublicSubnet1AZ2'
          - !Ref 'AWS::NoValue'
        Param3: !If
          - HasPublicSubnet1AZ3
          - !Ref 'PublicSubnet1AZ3'
          - !Ref 'AWS::NoValue'
    Export:
      Name: !Sub 'vpc-${Environment}-PublicSubnetIds'
```
Which CloudFormation complains about .. suggestions ??
diff --git a/tests/test_clean.py b/tests/test_clean.py
index 24e14a0..6fb9000 100644
--- a/tests/test_clean.py
+++ b/tests/test_clean.py
@@ -251,6 +251,84 @@ def test_deep_nested_join():
     assert expected == actual
 
 
+def test_gh_63_no_value():
+    """
+    Test that Joins with conditionals that can evaluate to AWS::NoValue
+    are not converted to Fn::Sub
+    """
+
+    source = {
+        "Fn::Join": [
+            ",",
+            [
+                {
+                    "Fn::If": [
+                        "Condition1",
+                        "True1",
+                        "AWS::NoValue"
+                    ]
+                },
+                {
+                    "Fn::If": [
+                        "Condition2",
+                        "True2",
+                        "False2"
+                    ]
+                }
+            ]
+        ]
+    }
+
+    assert source == clean(source)
+
+
+def test_gh_63_value():
+    """
+    Test that Joins with conditionals that cannot evaluate to AWS::NoValue
+    are converted to Fn::Sub
+    """
+
+    source = {
+        "Fn::Join": [
+            ",",
+            [
+                {
+                    "Fn::If": [
+                        "Condition1",
+                        "True1",
+                        "False1"
+                    ]
+                },
+                {
+                    "Fn::If": [
+                        "Condition2",
+                        "True2",
+                        "False2"
+                    ]
+                }
+            ]
+        ]
+    }
+
+    expected = ODict((
+        ("Fn::Sub", [
+            "${Param1},${Param2}",
+            ODict((
+                ("Param1", ODict((
+                    ("Fn::If", ["Condition1", "True1", "False1"]),
+                ))),
+                ("Param2", ODict((
+                    ("Fn::If", ["Condition2", "True2", "False2"]),
+                ))),
+            )),
+        ]),
+    ))
+
+    actual = clean(source)
+
+    assert actual == expected
+
+
 def test_misused_join():
     """
     Test that we don't break in the case that there is

pip install -e .
parse_log_pytest
requirements.txt
pytest pytest-cov pytest-sugar
3.6
requirements.txt
pytest --no-header -rA --tb=line --color=no -p no:cacheprovider -W ignore::DeprecationWarning
attrs==22.2.0
certifi==2021.5.30
-e git+https://github.com/awslabs/aws-cfn-template-flip.git@4b0f0936b5895db1ab74c124db140624deb6a7db#egg=cfn_flip
click==8.0.4
coverage==6.2
distlib==0.3.9
filelock==3.4.1
importlib-metadata==4.8.3
importlib-resources==5.4.0
iniconfig==1.1.1
packaging==21.3
platformdirs==2.4.0
pluggy==1.0.0
py==1.11.0
pyparsing==3.1.4
pytest==7.0.1
pytest-cov==4.0.0
pytest-sugar==0.9.6
PyYAML==6.0.1
six==1.17.0
termcolor==1.1.0
toml==0.10.2
tomli==1.2.3
tox==3.28.0
typing_extensions==4.1.1
virtualenv==20.17.1
zipp==3.6.0

name: aws-cfn-template-flip
channels:
  - defaults
  - https://repo.anaconda.com/pkgs/main
  - https://repo.anaconda.com/pkgs/r
  - conda-forge
dependencies:
  - _libgcc_mutex=0.1=main
  - _openmp_mutex=5.1=1_gnu
  - ca-certificates=2025.2.25=h06a4308_0
  - certifi=2021.5.30=py36h06a4308_0
  - ld_impl_linux-64=2.40=h12ee557_0
  - libffi=3.3=he6710b0_2
  - libgcc-ng=11.2.0=h1234567_1
  - libgomp=11.2.0=h1234567_1
  - libstdcxx-ng=11.2.0=h1234567_1
  - ncurses=6.4=h6a678d5_0
  - openssl=1.1.1w=h7f8727e_0
  - pip=21.2.2=py36h06a4308_0
  - python=3.6.13=h12debd9_1
  - readline=8.2=h5eee18b_0
  - setuptools=58.0.4=py36h06a4308_0
  - sqlite=3.45.3=h5eee18b_0
  - tk=8.6.14=h39e8969_0
  - wheel=0.37.1=pyhd3eb1b0_0
  - xz=5.6.4=h5eee18b_1
  - zlib=1.2.13=h5eee18b_1
  - pip:
      - attrs==22.2.0
      - click==8.0.4
      - coverage==6.2
      - distlib==0.3.9
      - filelock==3.4.1
      - importlib-metadata==4.8.3
      - importlib-resources==5.4.0
      - iniconfig==1.1.1
      - packaging==21.3
      - platformdirs==2.4.0
      - pluggy==1.0.0
      - py==1.11.0
      - pyparsing==3.1.4
      - pytest==7.0.1
      - pytest-cov==4.0.0
      - pytest-sugar==0.9.6
      - pyyaml==6.0.1
      - six==1.17.0
      - termcolor==1.1.0
      - toml==0.10.2
      - tomli==1.2.3
      - tox==3.28.0
      - typing-extensions==4.1.1
      - virtualenv==20.17.1
      - zipp==3.6.0
prefix: /opt/conda/envs/aws-cfn-template-flip

tests/test_clean.py::test_gh_63_no_value
tests/test_clean.py::test_basic_case tests/test_clean.py::test_ref tests/test_clean.py::test_get_att tests/test_clean.py::test_multi_level_get_att tests/test_clean.py::test_others tests/test_clean.py::test_in_array tests/test_clean.py::test_literals tests/test_clean.py::test_nested_join tests/test_clean.py::test_deep_nested_join tests/test_clean.py::test_gh_63_value tests/test_clean.py::test_misused_join tests/test_clean.py::test_yaml_dumper tests/test_clean.py::test_reused_sub_params
cfn_clean/__init__.py
cfn_clean/__init__.py