diff --git a/lib/core/extensions/harness/extension_manifest_validator.dart b/lib/core/extensions/harness/extension_manifest_validator.dart
index aab84e1c..541475d4 100644
--- a/lib/core/extensions/harness/extension_manifest_validator.dart
+++ b/lib/core/extensions/harness/extension_manifest_validator.dart
@@ -168,7 +168,11 @@ final _semver = RegExp(r'^\d+\.\d+\.\d+(?:[+-][0-9A-Za-z.+-]+)?$');
 /// as `>=0.4.0 <3.0.0`: `>=x.y.z`, `>x.y.z`, `<=x.y.z`, `<x.y.z`, `=x.y.z`,
 /// `^x.y.z` (same major, or the same minor while major is 0), or `*` alone.
 bool? engineRangeAllows(HostVersion host, String range) {
-  final parts = range.trim().split(RegExp(r'\s+'));
+  // `>= 0.4.0` reads the same as `>=0.4.0`: glue an operator to its version.
+  final parts = range
+      .trim()
+      .replaceAllMapped(RegExp(r'(>=|<=|>|<|=|\^)\s+'), (m) => m[1]!)
+      .split(RegExp(r'\s+'));
   if (parts.length == 1 && parts.single == '*') return true;
   var allowed = true;
   for (final part in parts) {
@@ -182,8 +186,8 @@ bool? engineRangeAllows(HostVersion host, String range) {
 bool? _comparatorAllows(HostVersion host, String c) {
   try {
     if (c.startsWith('>=')) return host >= HostVersion.parse(c.substring(2));
-    if (c.startsWith('<=')) return !(HostVersion.parse(c.substring(2)) < host);
-    if (c.startsWith('>')) return !(host <= HostVersion.parse(c.substring(1)));
+    if (c.startsWith('<=')) return host <= HostVersion.parse(c.substring(2));
+    if (c.startsWith('>')) return host > HostVersion.parse(c.substring(1));
     if (c.startsWith('<')) return host < HostVersion.parse(c.substring(1));
     if (c.startsWith('=')) return host == HostVersion.parse(c.substring(1));
     if (c.startsWith('^')) {
diff --git a/lib/core/extensions/harness/extension_protocol_profile.dart b/lib/core/extensions/harness/extension_protocol_profile.dart
index 5b85ff80..b03010ee 100644
--- a/lib/core/extensions/harness/extension_protocol_profile.dart
+++ b/lib/core/extensions/harness/extension_protocol_profile.dart
@@ -29,6 +29,7 @@ final class HostVersion implements Comparable<HostVersion> {
     return patch.compareTo(other.patch);
   }
 
+  bool operator >(HostVersion other) => compareTo(other) > 0;
   bool operator >=(HostVersion other) => compareTo(other) >= 0;
   bool operator <(HostVersion other) => compareTo(other) < 0;
   bool operator <=(HostVersion other) => compareTo(other) <= 0;
diff --git a/test/core/extensions/harness/extension_manifest_validator_test.dart b/test/core/extensions/harness/extension_manifest_validator_test.dart
index dc72bd00..6e06b078 100644
--- a/test/core/extensions/harness/extension_manifest_validator_test.dart
+++ b/test/core/extensions/harness/extension_manifest_validator_test.dart
@@ -125,6 +125,25 @@ void main() {
       expect(allows('0.5.0', '  >=0.4.0   <3.0.0 '), isTrue);
     });
 
+    test('spaces between an operator and its version are tolerated (#1635)',
+        () {
+      const range = '>= 0.4.0 < 3.0.0';
+      expect(allows('0.4.19', range), isTrue);
+      expect(allows('3.0.0', range), isFalse);
+      expect(allows('0.3.0', range), isFalse);
+      expect(allows('0.4.1', '> 0.4.0'), isTrue);
+      expect(allows('0.4.0', '<=  0.4.0'), isTrue);
+      expect(allows('0.4.19', '= 0.4.19'), isTrue);
+      expect(allows('0.4.19', '^ 0.4.11'), isTrue);
+      expect(allows('0.5.0', '>='), isNull);
+    });
+
+    test('HostVersion has a > operator (#1636)', () {
+      expect(HostVersion.parse('0.4.1') > HostVersion.parse('0.4.0'), isTrue);
+      expect(HostVersion.parse('0.4.0') > HostVersion.parse('0.4.0'), isFalse);
+      expect(HostVersion.parse('0.3.9') > HostVersion.parse('0.4.0'), isFalse);
+    });
+
     test('* means any version; a range it cannot read is null, not a guess', () {
       expect(allows('0.5.0', '*'), isTrue);
       for (final bad in ['~0.4', '>=0.4.0 || ^1.0.0', '>=x', '', '0.4.19', '* <3.0.0']) {