diff --git a/packages/react-devtools-shared/src/__tests__/inspectedElement-test.js b/packages/react-devtools-shared/src/__tests__/inspectedElement-test.js
index 09f811172f3..a73acd55bf4 100644
--- a/packages/react-devtools-shared/src/__tests__/inspectedElement-test.js
+++ b/packages/react-devtools-shared/src/__tests__/inspectedElement-test.js
@@ -582,6 +582,7 @@ describe('InspectedElement', () => {
           boolean_false={false}
           boolean_true={true}
           infinity={Infinity}
+          minus_infinity={-Infinity}
           integer_zero={0}
           integer_one={1}
           float={1.23}
@@ -604,6 +605,7 @@ describe('InspectedElement', () => {
         "infinity": Infinity,
         "integer_one": 1,
         "integer_zero": 0,
+        "minus_infinity": -Infinity,
         "nan": NaN,
         "string": "abc",
         "string_empty": "",
diff --git a/packages/react-devtools-shared/src/__tests__/legacy/inspectElement-test.js b/packages/react-devtools-shared/src/__tests__/legacy/inspectElement-test.js
index f306ab97093..62ba2e13608 100644
--- a/packages/react-devtools-shared/src/__tests__/legacy/inspectElement-test.js
+++ b/packages/react-devtools-shared/src/__tests__/legacy/inspectElement-test.js
@@ -98,6 +98,7 @@ describe('InspectedElementContext', () => {
           boolean_false: false,
           boolean_true: true,
           infinity: Infinity,
+          minus_infinity: -Infinity,
           integer_zero: 0,
           integer_one: 1,
           float: 1.23,
@@ -128,6 +129,7 @@ describe('InspectedElementContext', () => {
           "infinity": Infinity,
           "integer_one": 1,
           "integer_zero": 0,
+          "minus_infinity": -Infinity,
           "nan": NaN,
           "string": "abc",
           "string_empty": "",
diff --git a/packages/react-devtools-shared/src/devtools/utils.js b/packages/react-devtools-shared/src/devtools/utils.js
index 876e01345b4..43d3ea6c837 100644
--- a/packages/react-devtools-shared/src/devtools/utils.js
+++ b/packages/react-devtools-shared/src/devtools/utils.js
@@ -235,6 +235,8 @@ export function smartParse(value: any): any | void | number {
   switch (value) {
     case 'Infinity':
       return Infinity;
+    case '-Infinity':
+      return -Infinity;
     case 'NaN':
       return NaN;
     case 'undefined':
@@ -249,7 +251,7 @@ export function smartStringify(value: any): string {
     if (Number.isNaN(value)) {
       return 'NaN';
     } else if (!Number.isFinite(value)) {
-      return 'Infinity';
+      return value > 0 ? 'Infinity' : '-Infinity';
     }
   } else if (value === undefined) {
     return 'undefined';
diff --git a/packages/react-devtools-shared/src/devtools/views/Components/Tree.js b/packages/react-devtools-shared/src/devtools/views/Components/Tree.js
index 5623d507a3b..502056f936c 100644
--- a/packages/react-devtools-shared/src/devtools/views/Components/Tree.js
+++ b/packages/react-devtools-shared/src/devtools/views/Components/Tree.js
@@ -384,6 +384,23 @@ export default function Tree(): React.Node {
 
   const handleMouseLeave = clearHighlightHostInstance;
 
+  // The synthetic onMouseLeave on the tree div only fires within the document,
+  // so we need a native listener on the document itself.
+  useEffect(() => {
+    const container = focusTargetRef.current;
+    if (container == null) {
+      return;
+    }
+    const ownerDocument = container.ownerDocument;
+    ownerDocument.addEventListener('mouseleave', clearHighlightHostInstance);
+    return () => {
+      ownerDocument.removeEventListener(
+        'mouseleave',
+        clearHighlightHostInstance,
+      );
+    };
+  }, [clearHighlightHostInstance]);
+
   // Let react-window know to re-render any time the underlying tree data changes.
   // This includes the owner context, since it controls a filtered view of the tree.
   const itemData = useMemo<ItemData>(
diff --git a/packages/react-devtools-shared/src/hydration.js b/packages/react-devtools-shared/src/hydration.js
index 2468917d939..3670514ff4c 100644
--- a/packages/react-devtools-shared/src/hydration.js
+++ b/packages/react-devtools-shared/src/hydration.js
@@ -596,6 +596,7 @@ export function dehydrate(
       return value;
     }
     case 'infinity':
+    case '-infinity':
     case 'nan':
     case 'undefined':
       // Some values are lossy when sent through a WebSocket.
@@ -704,6 +705,8 @@ export function hydrate(
       return;
     } else if (value.type === 'infinity') {
       parent[last] = Infinity;
+    } else if (value.type === '-infinity') {
+      parent[last] = -Infinity;
     } else if (value.type === 'nan') {
       parent[last] = NaN;
     } else if (value.type === 'undefined') {
diff --git a/packages/react-devtools-shared/src/utils.js b/packages/react-devtools-shared/src/utils.js
index 66de8440b65..aa7ba33dc59 100644
--- a/packages/react-devtools-shared/src/utils.js
+++ b/packages/react-devtools-shared/src/utils.js
@@ -708,6 +708,7 @@ export type DataType =
   | 'html_all_collection'
   | 'html_element'
   | 'infinity'
+  | '-infinity'
   | 'iterator'
   | 'opaque_iterator'
   | 'nan'
@@ -765,7 +766,7 @@ export function getDataType(data: Object): DataType {
       if (Number.isNaN(data)) {
         return 'nan';
       } else if (!Number.isFinite(data)) {
-        return 'infinity';
+        return data > 0 ? 'infinity' : '-infinity';
       } else {
         return 'number';
       }
@@ -1219,6 +1220,7 @@ export function formatDataForPreview(
     case 'boolean':
     case 'number':
     case 'infinity':
+    case '-infinity':
     case 'nan':
     case 'null':
     case 'undefined':
diff --git a/packages/react-devtools-shell/src/app/InspectableElements/SimpleValues.js b/packages/react-devtools-shell/src/app/InspectableElements/SimpleValues.js
index 22c54ec91ee..1a17dc2279c 100644
--- a/packages/react-devtools-shell/src/app/InspectableElements/SimpleValues.js
+++ b/packages/react-devtools-shell/src/app/InspectableElements/SimpleValues.js
@@ -25,6 +25,7 @@ export default class SimpleValues extends Component {
         null={null}
         nan={NaN}
         infinity={Infinity}
+        minusInfinity={-Infinity}
         true={true}
         false={false}
         function={noop}