diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8360785..9ea03c6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,7 +6,14 @@ All notable changes to this project will be documented in this file. This projec
 
 Changes since last release will be listed here.
 
+## [v0.6.4] - 2022-06-21 - v0.6.4
+
 - Fixed the installation of ruamel.yaml if not already present.
+- Limit the ruamel.yaml version to less than 0.18.0, because newer versions are completely changed so will need more work to fix. Note that if you already have a newer version of ruamel.yaml in the python that you are using, it is advised to run the following command to remove it, after which running this script will reinstall a working version: 
+
+```
+/path/to/your/python -m pip uninstall ruamel.yaml
+```
 
 ## [v0.6.3] - 2022-06-21 - v0.6.3
 
@@ -58,7 +65,8 @@ Changes since last release will be listed here.
 
 - Initial Release (though the tool has been around for some time).
 
-[unreleased]: https://github.com/grahampugh/plist-yaml-plist/compare/v0.6.3...HEAD
+[unreleased]: https://github.com/grahampugh/plist-yaml-plist/compare/v0.6.4...HEAD
+[v0.6.4]: https://github.com/grahampugh/plist-yaml-plist/compare/v0.6.3...v0.6.4
 [v0.6.3]: https://github.com/grahampugh/plist-yaml-plist/compare/v0.6.1...v0.6.3
 [v0.6.1]: https://github.com/grahampugh/plist-yaml-plist/compare/v0.6.0...v0.6.1
 [v0.6.0]: https://github.com/grahampugh/plist-yaml-plist/compare/v0.5.0...v0.6.0
diff --git a/README.md b/README.md
index 954fd22..eae2a1c 100644
--- a/README.md
+++ b/README.md
@@ -6,11 +6,11 @@ It can also convert `json` files to `plist`.
 
 ## Prerequisites
 
-The python `ruamel.yaml` module is required, which is not installed by default on Macs. You can install it with `pip`, which you may also need to install first. A few other things need to be updated for ruamel to install:
+The python `ruamel.yaml` module is required, which is not installed by default on Macs. The version of ruamel.yaml currently must be lower than 0.18.0. You can install it with `pip`, which you may also need to install first. A few other things need to be updated for ruamel to install:
 
 ```bash
 python -m ensurepip --user
-python -m pip install -U pip setuptools wheel ruamel.yaml --user
+python -m pip install -U pip setuptools wheel ruamel.yaml<0.18.0 --user
 ```
 
 If you do not pre-install `ruamel.yaml`, the script will do it for you.
diff --git a/pkg/plistyamlplist/build-info.plist b/pkg/plistyamlplist/build-info.plist
index 7344c5e..98d835d 100644
--- a/pkg/plistyamlplist/build-info.plist
+++ b/pkg/plistyamlplist/build-info.plist
@@ -9,7 +9,7 @@
 	<key>install_location</key>
 	<string>/</string>
 	<key>name</key>
-	<string>plistyamlplist-0.6.3.pkg</string>
+	<string>plistyamlplist-0.6.4.pkg</string>
 	<key>ownership</key>
 	<string>recommended</string>
 	<key>postinstall_action</key>
@@ -17,6 +17,6 @@
 	<key>suppress_bundle_relocation</key>
 	<true/>
 	<key>version</key>
-	<string>0.6.3</string>
+	<string>0.6.4</string>
 </dict>
 </plist>
diff --git a/plistyamlplist_lib/plist_yaml.py b/plistyamlplist_lib/plist_yaml.py
index 2fcc046..bb2660d 100755
--- a/plistyamlplist_lib/plist_yaml.py
+++ b/plistyamlplist_lib/plist_yaml.py
@@ -39,7 +39,7 @@
             "pip",
             "setuptools",
             "wheel",
-            "ruamel.yaml",
+            "ruamel.yaml<0.18.0",
             "--user",
         ]
     )
diff --git a/plistyamlplist_lib/version.py b/plistyamlplist_lib/version.py
index 63af887..364e7ba 100644
--- a/plistyamlplist_lib/version.py
+++ b/plistyamlplist_lib/version.py
@@ -1 +1 @@
-__version__ = "0.6.3"
+__version__ = "0.6.4"
diff --git a/plistyamlplist_lib/yaml_plist.py b/plistyamlplist_lib/yaml_plist.py
index 350c14f..aa97761 100755
--- a/plistyamlplist_lib/yaml_plist.py
+++ b/plistyamlplist_lib/yaml_plist.py
@@ -36,7 +36,7 @@
             "pip",
             "setuptools",
             "wheel",
-            "ruamel.yaml",
+            "ruamel.yaml<0.18.0",
             "--user",
         ]
     )
diff --git a/plistyamlplist_lib/yaml_tidy.py b/plistyamlplist_lib/yaml_tidy.py
index 1da3894..ade0723 100755
--- a/plistyamlplist_lib/yaml_tidy.py
+++ b/plistyamlplist_lib/yaml_tidy.py
@@ -31,7 +31,7 @@
             "pip",
             "setuptools",
             "wheel",
-            "ruamel.yaml",
+            "ruamel.yaml<0.18.0",
             "--user",
         ]
     )