Address feedback.

CHANGELOG.md

@@ -5,7 +5,7 @@
 **Bug fixes**
 - Removed `.nvmrc` file from published npm package ([#892](https://github.com/elastic/eui/pull/892))
 - `EuiComboBox` no longer shows the _clear_ icon when it's a no-op ([#890](https://github.com/elastic/eui/pull/890))
-- `EuiIcon` no longer takes focus in Edge and IE unless `tabIndex='0'` is specified ([#900](https://github.com/elastic/eui/pull/900))
+- `EuiIcon` no longer takes focus in Edge and IE unless `tabIndex` is defined as a value other than `"-1"` ([#900](https://github.com/elastic/eui/pull/900))
 
 ## [`0.0.51`](https://github.com/elastic/eui/tree/v0.0.51)
 

src/components/icon/icon.js

@@ -394,8 +394,12 @@ export const EuiIcon = ({
   const Svg = typeToIconMap[type] || empty;
 
   // This is a fix for IE and Edge, which ignores tabindex="-1" on an SVG, but respects
-  // focusable="false". We want to default SVGs to *not* be focusable.
-  const focusable = tabIndex === '0' ? 'true' : 'false';
+  // focusable="false".
+  //   - If there's no tab index specified, we'll default the icon to not be focusable,
+  //     which is how SVGs behave in Chrome, Safari, and FF.
+  //   - If tab index is -1, then the consumer wants the icon to not be focusable.
+  //   - For all other values, the consumer wants the icon to be focusable.
+  const focusable = (!tabIndex || tabIndex === '-1') ? 'false' : 'true';
 
   return (
     <Svg