diff --git a/.svgo.yml b/.svgo.yml
index 313bf7c68..b9cb71454 100644
--- a/.svgo.yml
+++ b/.svgo.yml
@@ -49,7 +49,7 @@ plugins:
   - removeEmptyAttrs
   - removeEmptyContainers
   - mergePaths
-  - removeUnusedNS
+  - cleanupNS
   - sortAttrs
   - removeTitle
   - removeDesc
diff --git a/plugins/cleanupIDs.js b/plugins/cleanupIDs.js
index 2b61b93f7..070901ddb 100644
--- a/plugins/cleanupIDs.js
+++ b/plugins/cleanupIDs.js
@@ -29,14 +29,16 @@ var referencesProps = new Set(require('./_collections').referencesProps),
  * Remove unused and minify used IDs
  * (only if there are no any <style> or <script>).
  *
- * @param {Object} item current iteration item
+ * @param {Object} data full AST
  * @param {Object} params plugin params
+ * @return {Object} full AST
  *
  * @author Kir Belevich
  */
 exports.fn = function(data, params) {
     var currentID,
         currentIDstring,
+        currentIDmap,
         IDs = new Map(),
         referencesIDs = new Map(),
         hasStyleOrScript = false,
@@ -125,7 +127,10 @@ exports.fn = function(data, params) {
         if (IDs.has(key)) {
             // replace referenced IDs with the minified ones
             if (params.minify && !preserveIDs.has(key)) {
-                currentIDstring = getIDstring(currentID = generateID(currentID), params);
+                currentIDmap = generateID(currentID, preserveIDs, params);
+                currentID = currentIDmap.get('arr');
+                currentIDstring = currentIDmap.get('str');
+
                 IDs.get(key).attr('id').value = currentIDstring;
 
                 for (var attr of ref[1]) {
@@ -153,10 +158,12 @@ exports.fn = function(data, params) {
  * Generate unique minimal ID.
  *
  * @param {Array} [currentID] current ID
- * @return {Array} generated ID array
+ * @param {Set} preserveIDs IDs to be preserved
+ * @param {Object} params plugin params
+ * @return {Map} generated ID array and string
  */
-function generateID(currentID) {
-    if (!currentID) return [0];
+function generateID(currentID, preserveIDs, params) {
+    if (!currentID) currentID = [-1];
 
     currentID[currentID.length - 1]++;
 
@@ -173,13 +180,24 @@ function generateID(currentID) {
         currentID[0] = 0;
         currentID.unshift(0);
     }
-    return currentID;
+
+    var currentIDstring = getIDstring(currentID, params),
+        currentIDmap = new Map();
+
+    currentIDmap.set('arr', currentID);
+    currentIDmap.set('str', currentIDstring);
+
+    if (preserveIDs.size && preserveIDs.has(currentIDstring)) {
+        currentIDmap = generateID(currentID, preserveIDs, params);
+    }
+    return currentIDmap;
 }
 
 /**
  * Get string from generated ID array.
  *
  * @param {Array} arr input ID array
+ * @param {Object} params plugin params
  * @return {String} output ID string
  */
 function getIDstring(arr, params) {
diff --git a/plugins/cleanupNS.js b/plugins/cleanupNS.js
new file mode 100644
index 000000000..79ab32cac
--- /dev/null
+++ b/plugins/cleanupNS.js
@@ -0,0 +1,346 @@
+'use strict';
+
+exports.type = 'full';
+
+exports.active = true;
+
+exports.description = 'removes declarations of unused namespaces and minifies used namespace prefixes';
+
+exports.params = {
+    remove: true,
+    minify: true,
+    preserve: [],
+    force: true
+};
+
+var generatePrefixChars = [
+        'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
+        'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'
+    ],
+    maxPrefixIndex = generatePrefixChars.length - 1;
+
+/**
+ * Remove unused namespaces and minify used namespace prefixes.
+ *
+ * @param {Object} data full AST
+ * @param {Object} params plugin params
+ * @return {Object} full AST
+ *
+ * @author Kir Belevich
+ * @author James Thomson
+ */
+exports.fn = function(data, params) {
+    if (!params.remove && !params.minify) {
+        return data;
+    }
+
+    var styleOrScript = ['style', 'script'];
+    /**
+     * Find if the items contain a style or script elem.
+     *
+     * @param {Object} items the items to search in
+     */
+    function containsStyleOrScript(items) {
+        for (var i = 0; i < items.content.length && !hasStyleOrScript; i++) {
+            var item = items.content[i];
+
+            if (item.isElem(styleOrScript)) {
+                hasStyleOrScript = true;
+                break;
+            }
+
+            // go deeper
+            if (item.content) {
+                containsStyleOrScript(item);
+            }
+        }
+    }
+
+    // if 'force' param is false and the data contains a style or script elem
+    // then quit without changing anything
+    if (!params.force) {
+        var hasStyleOrScript = false;
+        containsStyleOrScript(data);
+
+        if (hasStyleOrScript) {
+            return data;
+        }
+    }
+
+    var currentNSPrefix,
+        nsesToPreserve = new Set(Array.isArray(params.preserve) ?
+            params.preserve : params.preserve ? [params.preserve] : []);
+    /**
+     * Remove and minify namespaces.
+     *
+     * @param {Object} items the items to work with
+     * @param {Map.<string, string>} prefixedAncestorNSes prefix for key, uri for value
+     * @param {string} [parentDefaultNSUri] the items' parent's default namespace uri
+     * @return {Map.<string, Array.<Object>>} references to namespaces declared in ancestors of 'items.content' elems
+     */
+    function cleanup(items, prefixedAncestorNSes, parentDefaultNSUri) {
+        // map of refs to return to the caller function
+        var refsForCaller = new Map();
+
+        for (var i = 0; i < items.content.length; i++) {
+            var item = items.content[i];
+
+            if (item.isElem()) {
+                var nsAttrs = getNSAttrs(item, nsesToPreserve, params);
+                var defaultNSUri = parentDefaultNSUri;
+
+                // this will only be true if 'remove' param is true
+                // and 'preserve' param does not contain 'xmlns'
+                if (nsAttrs.has('default')) {
+                    var defaultNSAttr = nsAttrs.get('default');
+
+                    if (defaultNSAttr.value === parentDefaultNSUri) {
+                        // the elem item's default namespace is unnecessary
+                        // so remove it
+                        item.removeAttr(defaultNSAttr.name);
+                    } else {
+                        defaultNSUri = defaultNSAttr.value;
+                    }
+                }
+
+                // make a map of prefixed namespaces to find references of
+                // in this element and its descendants
+                var nsesToFind = new Map(prefixedAncestorNSes);
+
+                var prefixedNSAttrs = nsAttrs.get('prefixed');
+                nsAttrs.clear();
+                var indicesToRemove = [];
+
+                prefixedNSAttrs.forEach((attr, index) => {
+                    if (params.remove &&
+                        prefixedAncestorNSes.get(attr.local) === attr.value) {
+                        // the namespace has the same prefix and uri as one
+                        // already in scope, from an ancestor, so remove the
+                        // current namespace attr
+                        item.removeAttr(attr.name);
+                        indicesToRemove.push(index - indicesToRemove.length);
+                    } else {
+                        // if the namespace has the same prefix as an ancestor
+                        // then we are no longer trying to find references to
+                        // the ancestor namespace, so overwrite the existing
+                        // value, if there is one
+                        nsesToFind.set(attr.local, attr.value);
+                    }
+                });
+
+                indicesToRemove.forEach(attrIndex => {
+                    prefixedNSAttrs.splice(attrIndex, 1);
+                });
+
+                // collect references, starting with the current elem
+                var nsRefs = new Map();
+                addNSReference(item, nsesToFind, nsRefs);
+
+                // now collect references from the item's attrs
+                item.eachAttr(attr => {
+                    if (attr.prefix !== 'xmlns') {
+                        addNSReference(attr, nsesToFind, nsRefs);
+                    }
+                });
+
+                // collect references from descendants
+                if (item.content) {
+                    var descendantNSRefs =
+                        cleanup(item, nsesToFind, defaultNSUri);
+
+                    // add the references from descendants to the existing
+                    // references, from the elem and its attrs
+                    nsRefs = combineMaps(nsRefs, descendantNSRefs);
+                }
+
+                // remove and minify namespace prefixes
+                prefixedNSAttrs.forEach(attr => {
+                    if (nsRefs.has(attr.local)) {
+                        var originalNSPrefix = attr.local;
+
+                        if (params.minify) {
+                            var currentNSPrefixMap =
+                                generateNSPrefix(
+                                    currentNSPrefix,
+                                    nsesToPreserve
+                                );
+
+                            currentNSPrefix = currentNSPrefixMap.get('arr');
+                            var currentNSPrefixString =
+                                currentNSPrefixMap.get('str');
+
+                            nsRefs.get(originalNSPrefix).forEach(ref => {
+                                var refProperty = ref.hasOwnProperty('elem') ?
+                                    'elem' : 'name';
+
+                                ref.prefix = currentNSPrefixString;
+                                ref[refProperty] = ref.prefix + ':' + ref.local;
+                            });
+
+                            attr.local = currentNSPrefixString;
+                            attr.name = 'xmlns:' + attr.local;
+                        }
+
+                        nsRefs.delete(originalNSPrefix);
+                    } else if (params.remove) {
+                        // the namespace is not referenced so remove it
+                        item.removeAttr(attr.name);
+                    }
+                });
+
+                // add the remaining refs to the map to be returned
+                refsForCaller = combineMaps(refsForCaller, nsRefs);
+            }
+        }
+
+        return refsForCaller;
+    }
+
+    cleanup(data, new Map());
+    return data;
+};
+
+/**
+ * Get all of the namespace attributes from the input element's attributes.
+ *
+ * @param {Object} elem elem to find namespace attrs in
+ * @param {Set.<string>} nsesToPreserve namespaces to preserve (all prefixes, with the possible exception being 'xmlns')
+ * @param {Object} params plugin params
+ * @return {Map.<string, (Object|Array.<Object>)>} default namespace attr and array of prefixed namespace attrs
+ */
+function getNSAttrs(elem, nsesToPreserve, params) {
+    var nsAttrs = new Map();
+    var prefixed = [];
+
+    Object.keys(elem.attrs).forEach(key => {
+        if (elem.attrs[key].prefix === 'xmlns') {
+            if (elem.attrs[key].local) {
+                // don't add namespace attrs with prefixes that are to be
+                // preserved, as we don't need to find references to them
+                if (!nsesToPreserve.has(elem.attrs[key].local)) {
+                    // don't add 'xml' namespace prefix attr, as it shouldn't be
+                    // minified, and remove it, if allowed, as it is optional
+                    if (elem.attrs[key].local === 'xml') {
+                        if (params.remove) {
+                            elem.removeAttr(elem.attrs[key].name);
+                        }
+                    } else {
+                        prefixed.push(elem.attrs[key]);
+                    }
+                }
+            // since all namespace prefixes starting with 'xml',
+            // in any case combination, are reserved, 'xmlns' can be used to
+            // preserve the default namespace, and as it cannot be minified,
+            // only add it if we are allowed to remove namespaces
+            } else if (params.remove && !nsesToPreserve.has('xmlns')) {
+                nsAttrs.set('default', elem.attrs[key]);
+            }
+        }
+    });
+
+    nsAttrs.set('prefixed', prefixed);
+    return nsAttrs;
+}
+
+/**
+ * Add a reference to a prefixed namespace in scope.
+ *
+ * @param {Object} item elem or attr
+ * @param {Map.<string, string>} nsesToFind the prefixed namespaces in scope
+ * @param {Map.<string, Array.<Object>>} nsRefs map of namespace references, with array of items as the value
+ */
+function addNSReference(item, nsesToFind, nsRefs) {
+    if (item.prefix && nsesToFind.has(item.prefix)) {
+        var refs = nsRefs.has(item.prefix) ?
+            nsRefs.get(item.prefix) : [];
+
+        refs.push(item);
+        nsRefs.set(item.prefix, refs);
+    }
+}
+
+/**
+ * Generate a unique, minimal namespace prefix (mostly taken from 'cleanupIDs plugin').
+ *
+ * @param {Array.<number>} currentNSPrefix array used to make prefix string
+ * @param {Set.<string>} nsesToPreserve namespaces to preserve
+ * @return {Map.<string, (string|Array.<number>)>} generated namespace prefix array and string
+ */
+function generateNSPrefix(currentNSPrefix, nsesToPreserve) {
+    if (!currentNSPrefix) currentNSPrefix = [-1];
+
+    currentNSPrefix[currentNSPrefix.length - 1]++;
+
+    for (var i = currentNSPrefix.length - 1; i > 0; i--) {
+        if (currentNSPrefix[i] > maxPrefixIndex) {
+            currentNSPrefix[i] = 0;
+
+            if (currentNSPrefix[i - 1] !== undefined) {
+                currentNSPrefix[i - 1]++;
+            }
+        }
+    }
+
+    if (currentNSPrefix[0] > maxPrefixIndex) {
+        currentNSPrefix[0] = 0;
+        currentNSPrefix.unshift(0);
+    }
+    // prefixes beginning with 'xml', in any case combination, are reserved
+    // (https://www.w3.org/TR/xml-names/#ns-decl) so don't allow
+    // the array to start like this
+    if (currentNSPrefix.length > 2 &&
+        (generatePrefixChars[currentNSPrefix[0]] +
+            generatePrefixChars[currentNSPrefix[1]] +
+            generatePrefixChars[currentNSPrefix[2]]).toLowerCase() === 'xml') {
+        currentNSPrefix[2]++;
+    }
+
+    var currentNSPrefixString = getNSPrefixString(currentNSPrefix),
+        currentNSPrefixMap = new Map();
+
+    currentNSPrefixMap.set('arr', currentNSPrefix);
+    currentNSPrefixMap.set('str', currentNSPrefixString);
+
+    // don't let the string be equal to a preserved namespace prefix
+    if (nsesToPreserve.size && nsesToPreserve.has(currentNSPrefixString)) {
+        currentNSPrefixMap = generateNSPrefix(currentNSPrefix, nsesToPreserve);
+    }
+
+    return currentNSPrefixMap;
+}
+
+/**
+ * Get string from generated namespace prefix array.
+ *
+ * @param {Array.<number>} currentNSPrefix array to make the string from
+ * @return {string} string created
+ */
+function getNSPrefixString(currentNSPrefix) {
+    return currentNSPrefix.map(i => generatePrefixChars[i]).join('');
+}
+
+/**
+ * Add the references from map2 to map1 and return map1.
+ *
+ * @param {Map.<string, Array.<Object>>} map1 the map to return
+ * @param {Map.<string, Array.<Object>>} map2 the map to add to map1
+ * @return {Map.<string, Array.<Object>>} the combined map
+ */
+function combineMaps(map1, map2) {
+    if(!map1.size) {
+        map1 = map2;
+    } else if(map2.size) {
+        map2.forEach((refs, prefix) => {
+            if (map1.has(prefix)) {
+                map1.set(
+                    prefix,
+                    map1.get(prefix).concat(refs)
+                );
+            } else {
+                map1.set(prefix, refs);
+            }
+        });
+    }
+
+    return map1;
+}
diff --git a/plugins/removeUnusedNS.js b/plugins/removeUnusedNS.js
deleted file mode 100644
index c4787915e..000000000
--- a/plugins/removeUnusedNS.js
+++ /dev/null
@@ -1,107 +0,0 @@
-'use strict';
-
-exports.type = 'full';
-
-exports.active = true;
-
-exports.description = 'removes unused namespaces declaration';
-
-/**
- * Remove unused namespaces declaration.
- *
- * @param {Object} item current iteration item
- * @return {Boolean} if false, item will be filtered out
- *
- * @author Kir Belevich
- */
-exports.fn = function(data) {
-
-    var svgElem,
-        xmlnsCollection = [];
-
-    /**
-     * Remove namespace from collection.
-     *
-     * @param {String} ns namescape name
-     */
-    function removeNSfromCollection(ns) {
-
-        var pos = xmlnsCollection.indexOf(ns);
-
-        // if found - remove ns from the namespaces collection
-        if (pos > -1) {
-            xmlnsCollection.splice(pos, 1);
-        }
-
-    }
-
-    /**
-     * Bananas!
-     *
-     * @param {Array} items input items
-     *
-     * @return {Array} output items
-     */
-    function monkeys(items) {
-
-        var i = 0,
-            length = items.content.length;
-
-        while(i < length) {
-
-            var item = items.content[i];
-
-            if (item.isElem('svg')) {
-
-                item.eachAttr(function(attr) {
-                    // collect namespaces
-                    if (attr.prefix === 'xmlns' && attr.local) {
-                        xmlnsCollection.push(attr.local);
-                    }
-                });
-
-                // if svg element has ns-attr
-                if (xmlnsCollection.length) {
-                    // save svg element
-                    svgElem = item;
-                }
-
-            } else if (xmlnsCollection.length) {
-
-                // check item for the ns-attrs
-                if (item.prefix) {
-                    removeNSfromCollection(item.prefix);
-                }
-
-                // check each attr for the ns-attrs
-                item.eachAttr(function(attr) {
-                    removeNSfromCollection(attr.prefix);
-                });
-
-            }
-
-            // if nothing is found - go deeper
-            if (xmlnsCollection.length && item.content) {
-                monkeys(item);
-            }
-
-            i++;
-
-        }
-
-        return items;
-
-    }
-
-    data = monkeys(data);
-
-    // remove svg element ns-attributes if they are not used even once
-    if (xmlnsCollection.length) {
-        xmlnsCollection.forEach(function(name) {
-            svgElem.removeAttr('xmlns:' + name);
-        });
-    }
-
-    return data;
-
-};
diff --git a/test/plugins/cleanupIDs.12.svg b/test/plugins/cleanupIDs.12.svg
new file mode 100644
index 000000000..79c684d0d
--- /dev/null
+++ b/test/plugins/cleanupIDs.12.svg
@@ -0,0 +1,25 @@
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
+    <g id="a">
+        test
+    </g>
+    <g id="test">
+        test
+    </g>
+    <use xlink:href="#test"/>
+</svg>
+
+@@@
+
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
+    <g id="a">
+        test
+    </g>
+    <g id="b">
+        test
+    </g>
+    <use xlink:href="#b"/>
+</svg>
+
+@@@
+
+{"preserve": "a"}
diff --git a/test/plugins/removeUnusedNS.01.svg b/test/plugins/cleanupNS.01.svg
similarity index 100%
rename from test/plugins/removeUnusedNS.01.svg
rename to test/plugins/cleanupNS.01.svg
diff --git a/test/plugins/removeUnusedNS.02.svg b/test/plugins/cleanupNS.02.svg
similarity index 92%
rename from test/plugins/removeUnusedNS.02.svg
rename to test/plugins/cleanupNS.02.svg
index 33331da33..ff7234ec9 100644
--- a/test/plugins/removeUnusedNS.02.svg
+++ b/test/plugins/cleanupNS.02.svg
@@ -11,3 +11,7 @@
         test
     </g>
 </svg>
+
+@@@
+
+{"minify": false}
diff --git a/test/plugins/removeUnusedNS.03.svg b/test/plugins/cleanupNS.03.svg
similarity index 94%
rename from test/plugins/removeUnusedNS.03.svg
rename to test/plugins/cleanupNS.03.svg
index e142667f5..6ca1dbaa3 100644
--- a/test/plugins/removeUnusedNS.03.svg
+++ b/test/plugins/cleanupNS.03.svg
@@ -15,3 +15,7 @@
         </g>
     </g>
 </svg>
+
+@@@
+
+{"minify": false}
diff --git a/test/plugins/removeUnusedNS.04.svg b/test/plugins/cleanupNS.04.svg
similarity index 95%
rename from test/plugins/removeUnusedNS.04.svg
rename to test/plugins/cleanupNS.04.svg
index cf4f98b3f..d478f63c9 100644
--- a/test/plugins/removeUnusedNS.04.svg
+++ b/test/plugins/cleanupNS.04.svg
@@ -15,3 +15,7 @@
         </g>
     </g>
 </svg>
+
+@@@
+
+{"minify": false}
diff --git a/test/plugins/removeUnusedNS.05.svg b/test/plugins/cleanupNS.05.svg
similarity index 94%
rename from test/plugins/removeUnusedNS.05.svg
rename to test/plugins/cleanupNS.05.svg
index d7914b5ec..274ac5a8d 100644
--- a/test/plugins/removeUnusedNS.05.svg
+++ b/test/plugins/cleanupNS.05.svg
@@ -15,3 +15,7 @@
         </test:elem>
     </g>
 </svg>
+
+@@@
+
+{"minify": false}
diff --git a/test/plugins/removeUnusedNS.06.svg b/test/plugins/cleanupNS.06.svg
similarity index 95%
rename from test/plugins/removeUnusedNS.06.svg
rename to test/plugins/cleanupNS.06.svg
index 9ec89fbb5..1137cc00d 100644
--- a/test/plugins/removeUnusedNS.06.svg
+++ b/test/plugins/cleanupNS.06.svg
@@ -15,3 +15,7 @@
         </test2:elem>
     </test:elem>
 </svg>
+
+@@@
+
+{"minify": false}
diff --git a/test/plugins/cleanupNS.07.svg b/test/plugins/cleanupNS.07.svg
new file mode 100644
index 000000000..18df5e4ba
--- /dev/null
+++ b/test/plugins/cleanupNS.07.svg
@@ -0,0 +1,13 @@
+<svg xmlns="http://www.w3.org/2000/svg">
+    <g xmlns="http://www.w3.org/2000/svg">
+        test
+    </g>
+</svg>
+
+@@@
+
+<svg xmlns="http://www.w3.org/2000/svg">
+    <g>
+        test
+    </g>
+</svg>
diff --git a/test/plugins/cleanupNS.08.svg b/test/plugins/cleanupNS.08.svg
new file mode 100644
index 000000000..64d4edec7
--- /dev/null
+++ b/test/plugins/cleanupNS.08.svg
@@ -0,0 +1,17 @@
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:test="http://trololololololololololo.com/">
+    <g xmlns:test="http://trololololololololololo.com/" test:attr="val">
+        test
+    </g>
+</svg>
+
+@@@
+
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:test="http://trololololololololololo.com/">
+    <g test:attr="val">
+        test
+    </g>
+</svg>
+
+@@@
+
+{"minify": false}
diff --git a/test/plugins/cleanupNS.09.svg b/test/plugins/cleanupNS.09.svg
new file mode 100644
index 000000000..363057329
--- /dev/null
+++ b/test/plugins/cleanupNS.09.svg
@@ -0,0 +1,17 @@
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:test="http://www.example.org/wine">
+    <g xmlns:test="http://trololololololololololo.com/" test:attr="val">
+        test
+    </g>
+</svg>
+
+@@@
+
+<svg xmlns="http://www.w3.org/2000/svg">
+    <g xmlns:test="http://trololololololololololo.com/" test:attr="val">
+        test
+    </g>
+</svg>
+
+@@@
+
+{"minify": false}
diff --git a/test/plugins/cleanupNS.10.svg b/test/plugins/cleanupNS.10.svg
new file mode 100644
index 000000000..d1e36662a
--- /dev/null
+++ b/test/plugins/cleanupNS.10.svg
@@ -0,0 +1,13 @@
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:test="http://trololololololololololo.com/">
+    <g test:attr="val">
+        test
+    </g>
+</svg>
+
+@@@
+
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:a="http://trololololololololololo.com/">
+    <g a:attr="val">
+        test
+    </g>
+</svg>
diff --git a/test/plugins/cleanupNS.11.svg b/test/plugins/cleanupNS.11.svg
new file mode 100644
index 000000000..f9d25c716
--- /dev/null
+++ b/test/plugins/cleanupNS.11.svg
@@ -0,0 +1,19 @@
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:test="http://trololololololololololo.com/">
+    <style>
+        …
+    </style>
+    <g test:attr="val">
+        test
+    </g>
+</svg>
+
+@@@
+
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:a="http://trololololololololololo.com/">
+    <style>
+        …
+    </style>
+    <g a:attr="val">
+        test
+    </g>
+</svg>
diff --git a/test/plugins/cleanupNS.12.svg b/test/plugins/cleanupNS.12.svg
new file mode 100644
index 000000000..8faa9e62c
--- /dev/null
+++ b/test/plugins/cleanupNS.12.svg
@@ -0,0 +1,23 @@
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:test="http://trololololololololololo.com/">
+    <style>
+        …
+    </style>
+    <g test:attr="val">
+        test
+    </g>
+</svg>
+
+@@@
+
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:test="http://trololololololololololo.com/">
+    <style>
+        …
+    </style>
+    <g test:attr="val">
+        test
+    </g>
+</svg>
+
+@@@
+
+{"force": false}
diff --git a/test/plugins/cleanupNS.13.svg b/test/plugins/cleanupNS.13.svg
new file mode 100644
index 000000000..4abfd94d0
--- /dev/null
+++ b/test/plugins/cleanupNS.13.svg
@@ -0,0 +1,19 @@
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:test="http://trololololololololololo.com/">
+    <script>
+        …
+    </script>
+    <g test:attr="val">
+        test
+    </g>
+</svg>
+
+@@@
+
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:a="http://trololololololololololo.com/">
+    <script>
+        …
+    </script>
+    <g a:attr="val">
+        test
+    </g>
+</svg>
diff --git a/test/plugins/cleanupNS.14.svg b/test/plugins/cleanupNS.14.svg
new file mode 100644
index 000000000..2e4ed7d89
--- /dev/null
+++ b/test/plugins/cleanupNS.14.svg
@@ -0,0 +1,23 @@
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:test="http://trololololololololololo.com/">
+    <script>
+        …
+    </script>
+    <g test:attr="val">
+        test
+    </g>
+</svg>
+
+@@@
+
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:test="http://trololololololololololo.com/">
+    <script>
+        …
+    </script>
+    <g test:attr="val">
+        test
+    </g>
+</svg>
+
+@@@
+
+{"force": false}
diff --git a/test/plugins/cleanupNS.15.svg b/test/plugins/cleanupNS.15.svg
new file mode 100644
index 000000000..1f467a94d
--- /dev/null
+++ b/test/plugins/cleanupNS.15.svg
@@ -0,0 +1,17 @@
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:test="http://trololololololololololo.com/">
+    <g>
+        test
+    </g>
+</svg>
+
+@@@
+
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:test="http://trololololololololololo.com/">
+    <g>
+        test
+    </g>
+</svg>
+
+@@@
+
+{"remove": false}
diff --git a/test/plugins/cleanupNS.16.svg b/test/plugins/cleanupNS.16.svg
new file mode 100644
index 000000000..8ff776e15
--- /dev/null
+++ b/test/plugins/cleanupNS.16.svg
@@ -0,0 +1,21 @@
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:test="http://trololololololololololo.com/" xmlns:test2="http://trololololololololololo.com/">
+    <g test:attr="val">
+        <g test2:attr="val">
+            test
+        </g>
+    </g>
+</svg>
+
+@@@
+
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:a="http://trololololololololololo.com/" xmlns:test2="http://trololololololololololo.com/">
+    <g a:attr="val">
+        <g test2:attr="val">
+            test
+        </g>
+    </g>
+</svg>
+
+@@@
+
+{"preserve": "test2"}
diff --git a/test/plugins/cleanupNS.17.svg b/test/plugins/cleanupNS.17.svg
new file mode 100644
index 000000000..6aaab924f
--- /dev/null
+++ b/test/plugins/cleanupNS.17.svg
@@ -0,0 +1,17 @@
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:test="http://trololololololololololo.com/" xmlns:test2="http://trololololololololololo.com/">
+    <g test:attr="val">
+        test
+    </g>
+</svg>
+
+@@@
+
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:a="http://trololololololololololo.com/" xmlns:test2="http://trololololololololololo.com/">
+    <g a:attr="val">
+        test
+    </g>
+</svg>
+
+@@@
+
+{"preserve": "test2"}
diff --git a/test/plugins/cleanupNS.18.svg b/test/plugins/cleanupNS.18.svg
new file mode 100644
index 000000000..a1b7af27f
--- /dev/null
+++ b/test/plugins/cleanupNS.18.svg
@@ -0,0 +1,17 @@
+<svg xmlns="http://www.w3.org/2000/svg">
+    <g xmlns="http://www.w3.org/2000/svg">
+        test
+    </g>
+</svg>
+
+@@@
+
+<svg xmlns="http://www.w3.org/2000/svg">
+    <g xmlns="http://www.w3.org/2000/svg">
+        test
+    </g>
+</svg>
+
+@@@
+
+{"preserve": "xmlns"}
diff --git a/test/plugins/cleanupNS.19.svg b/test/plugins/cleanupNS.19.svg
new file mode 100644
index 000000000..b2c81e70d
--- /dev/null
+++ b/test/plugins/cleanupNS.19.svg
@@ -0,0 +1,13 @@
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:xml="http://www.w3.org/XML/1998/namespace">
+    <g>
+        test
+    </g>
+</svg>
+
+@@@
+
+<svg xmlns="http://www.w3.org/2000/svg">
+    <g>
+        test
+    </g>
+</svg>
diff --git a/test/plugins/cleanupNS.20.svg b/test/plugins/cleanupNS.20.svg
new file mode 100644
index 000000000..8658c666b
--- /dev/null
+++ b/test/plugins/cleanupNS.20.svg
@@ -0,0 +1,17 @@
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:xml="http://www.w3.org/XML/1998/namespace">
+    <g>
+        test
+    </g>
+</svg>
+
+@@@
+
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:xml="http://www.w3.org/XML/1998/namespace">
+    <g>
+        test
+    </g>
+</svg>
+
+@@@
+
+{"preserve": "xml"}
diff --git a/test/plugins/cleanupNS.21.svg b/test/plugins/cleanupNS.21.svg
new file mode 100644
index 000000000..d7ed24762
--- /dev/null
+++ b/test/plugins/cleanupNS.21.svg
@@ -0,0 +1,17 @@
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:a="http://www.example.org/wine" xmlns:test="http://trololololololololololo.com/">
+    <test:elem test:attr="val">
+        test
+    </test:elem>
+</svg>
+
+@@@
+
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:a="http://www.example.org/wine" xmlns:b="http://trololololololololololo.com/">
+    <b:elem b:attr="val">
+        test
+    </b:elem>
+</svg>
+
+@@@
+
+{"preserve": "a"}
diff --git a/test/plugins/cleanupNS.22.svg b/test/plugins/cleanupNS.22.svg
new file mode 100644
index 000000000..97c478385
--- /dev/null
+++ b/test/plugins/cleanupNS.22.svg
@@ -0,0 +1,23 @@
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:test="http://trololololololololololo.com/">
+    <g test:attr="val">
+        test
+    </g>
+    <g xmlns="http://trololololololololololo.com/" xmlns:test="http://www.example.org/wine">
+        <g test:attr="val" xmlns:test="http://trololololololololololo.com/" xmlns="http://www.w3.org/2000/svg">
+            test
+        </g>
+    </g>
+</svg>
+
+@@@
+
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:b="http://trololololololololololo.com/">
+    <g b:attr="val">
+        test
+    </g>
+    <g xmlns="http://trololololololololololo.com/">
+        <g a:attr="val" xmlns:a="http://trololololololololololo.com/" xmlns="http://www.w3.org/2000/svg">
+            test
+        </g>
+    </g>
+</svg>