diff --git a/src/XacroParser.js b/src/XacroParser.js
index 3848841..ca1edc1 100644
--- a/src/XacroParser.js
+++ b/src/XacroParser.js
@@ -223,7 +223,9 @@ export class XacroParser {
 
                 obj.name = name;
                 if (def.startsWith('\'') && def.endsWith('\'')) {
-                    obj.def = def.substr(1, def.length - 2);
+                    // strip quotes from the default value if it happens to be a string like so:
+                    // a:='0.0 1.0 2.0'
+                    obj.def = def.substring(1, def.length - 1);
                 } else {
                     obj.def = def;
                 }
@@ -244,9 +246,10 @@ export class XacroParser {
             // parse params
             const inputMap = {};
             if (params) {
+                // find param definitions including string values like a:='0.0 1.0 2.0'
                 const inputs = params
                     .trim()
-                    .match(/[^\s']+(['][^']*['])?/g)
+                    .match(/[^\s']+('[^']*')?/g)
                     .map(s => parseMacroParam(s));
                 inputs.forEach(inp => {
                     inputMap[inp.name] = inp;
diff --git a/test/XacroLoader.test.js b/test/XacroLoader.test.js
index eb327c8..f455d9c 100644
--- a/test/XacroLoader.test.js
+++ b/test/XacroLoader.test.js
@@ -254,6 +254,33 @@ describe('XacroLoader', () => {
             );
         });
 
+        it.only('should resolve params and defaults with string properties.', done => {
+            const content =
+                `<?xml version="1.0"?>
+                <robot xmlns:xacro="http://ros.org/wiki/xacro">
+                    <xacro:property name="input" value="10"/>
+                    <xacro:macro name="test" params="a:='1.0 2.0 3.0' b:='1.0 2.0'">
+                        <child a="\${a}" b="\${b}"/>
+                    </xacro:macro>
+                    <xacro:test/>
+                    <xacro:test a="1"/>
+                </robot>
+            `;
+            const loader = new XacroLoader();
+            loader.parse(
+                content, res => {
+                    const str = new XMLSerializer().serializeToString(res);
+                    expect(unformat(str)).toEqual(unformat(
+                        `<robot>
+                            <child a="1.0 2.0 3.0" b="1.0 2.0"/>
+                            <child a="1" b="1.0 2.0"/>
+                        </robot>`,
+                    ));
+                    done();
+                },
+            );
+        });
+
         it('should throw an error if a parameter cannot be resolved.', done => {
             const content =
                 `<?xml version="1.0"?>