diff --git a/pkg/native_stack_traces/CHANGELOG.md b/pkg/native_stack_traces/CHANGELOG.md
index 38b806bcaf4..2d4d9d9a1b8 100644
--- a/pkg/native_stack_traces/CHANGELOG.md
+++ b/pkg/native_stack_traces/CHANGELOG.md
@@ -1,3 +1,11 @@
+## 0.5.5
+
+- Fixed issue introduced by 0.5.4.
+
+## 0.5.4
+
+- Relaxed requirement for spaces before non-symbolic stack trace line.
+
 ## 0.5.3
 
 - Exported more ELF utilities for use in Dart tests.
diff --git a/pkg/native_stack_traces/lib/src/convert.dart b/pkg/native_stack_traces/lib/src/convert.dart
index de255d01955..50ef580d7cb 100644
--- a/pkg/native_stack_traces/lib/src/convert.dart
+++ b/pkg/native_stack_traces/lib/src/convert.dart
@@ -125,9 +125,9 @@ const _symbolOffsetREString = r'(?<symbol>' +
     constants.isolateSymbolName +
     r')\+(?<offset>(?:0x)?[\da-f]+)';
 final _symbolOffsetRE = RegExp(_symbolOffsetREString);
-final _traceLineRE = RegExp(
-    r'    #(\d+) abs (?<absolute>[\da-f]+)(?: virt (?<virtual>[\da-f]+))? '
-    r'(?<rest>.*)$');
+final _traceLineRE =
+    RegExp(r'\s*#(\d+) abs (?<absolute>[\da-f]+)(?: virt (?<virtual>[\da-f]+))?'
+        r' (?<rest>.*)$');
 
 /// Parses strings of the format <static symbol>+<integer offset>, where
 /// <static symbol> is one of the static symbols used for Dart instruction
@@ -272,8 +272,15 @@ class DwarfStackTraceDecoder extends StreamTransformerBase<String, String> {
       // No lines to output (as this corresponds to Dart internals).
       if (callInfo.isEmpty) continue;
       // Output the lines for the symbolic frame with the prefix found on the
-      // original non-symbolic frame line.
-      final prefix = line.substring(0, lineMatch!.start);
+      // original non-symbolic frame line, modulo all whitespace between the
+      // prefix and stack trace information converted to a single space.
+      //
+      // If there was no prefix, just swallow any initial whitespace, since
+      // symbolic Dart stacktrace lines have no initial whitespace.
+      String prefix = line.substring(0, lineMatch!.start);
+      if (prefix.isNotEmpty) {
+        prefix += ' ';
+      }
       for (final call in callInfo) {
         yield prefix + _stackTracePiece(call, depth++);
       }
diff --git a/pkg/native_stack_traces/pubspec.yaml b/pkg/native_stack_traces/pubspec.yaml
index 39174a6e522..6af398d8e92 100644
--- a/pkg/native_stack_traces/pubspec.yaml
+++ b/pkg/native_stack_traces/pubspec.yaml
@@ -1,5 +1,5 @@
 name: native_stack_traces
-version: 0.5.3
+version: 0.5.5
 description: Utilities for working with non-symbolic stack traces.
 repository: https://github.com/dart-lang/sdk/tree/main/pkg/native_stack_traces
 
@@ -19,3 +19,4 @@ dependencies:
 # See also https://dart.dev/tools/pub/dependencies.
 dev_dependencies:
   lints: any
+  test: any
diff --git a/pkg/native_stack_traces/test/convert/regress_262474517_test.dart b/pkg/native_stack_traces/test/convert/regress_262474517_test.dart
new file mode 100644
index 00000000000..8a3f2eed1fb
--- /dev/null
+++ b/pkg/native_stack_traces/test/convert/regress_262474517_test.dart
@@ -0,0 +1,39 @@
+// Copyright (c) 2022, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'dart:io';
+
+import 'package:native_stack_traces/src/convert.dart';
+import 'package:native_stack_traces/src/dwarf.dart';
+import 'package:path/path.dart' as path;
+import 'package:test/test.dart';
+
+void main() {
+  group('convert tests', defineConvertTests);
+}
+
+final String pkgDir = Platform.script.resolve('../..').toFilePath();
+
+void defineConvertTests() {
+  test('b/262474517 regression', () async {
+    final inputDir = path.join(pkgDir, 'testcases', 'convert');
+    // Test with a prefix without four spaces between prefix and trace.
+    testPath(path.join(inputDir, 'regress_262474517_trace.txt'));
+    // Test for no prefix or whitespace at all.
+    testPath(path.join(inputDir, 'regress_262474517_trace_2.txt'));
+  });
+}
+
+void testPath(String inputPath) async {
+  final contents = await File(inputPath).readAsLines();
+  final pcOffsets = collectPCOffsets(contents);
+  expect(pcOffsets.map((o) => o.offset).toList(),
+      [0x14e87f, 0x2a4e27, 0x4ee12b, 0x477fc7]);
+  expect(pcOffsets.map((o) => o.section).toList(), [
+    InstructionsSection.isolate,
+    InstructionsSection.isolate,
+    InstructionsSection.isolate,
+    InstructionsSection.isolate
+  ]);
+}
diff --git a/pkg/native_stack_traces/testcases/convert/regress_262474517_trace.txt b/pkg/native_stack_traces/testcases/convert/regress_262474517_trace.txt
new file mode 100644
index 00000000000..15cfbed2b35
--- /dev/null
+++ b/pkg/native_stack_traces/testcases/convert/regress_262474517_trace.txt
@@ -0,0 +1,6 @@
+Non-fatal Exception: io.flutter.plugins.firebase.crashlytics.FlutterError: Bad state: No element. Error thrown null.
+BuildId: c3126a4381294e13185549e5e94a4db9
+at . #00 abs 0 virt 000000000031ba6f _kDartIsolateSnapshotInstructions+0x14e87f
+at . #01 abs 0 virt 0000000000472017 _kDartIsolateSnapshotInstructions+0x2a4e27
+at . #02 abs 0 virt 00000000006bb31b _kDartIsolateSnapshotInstructions+0x4ee12b
+at . #03 abs 0 virt 00000000006451b7 _kDartIsolateSnapshotInstructions+0x477fc7
diff --git a/pkg/native_stack_traces/testcases/convert/regress_262474517_trace_2.txt b/pkg/native_stack_traces/testcases/convert/regress_262474517_trace_2.txt
new file mode 100644
index 00000000000..f1287a3d2ac
--- /dev/null
+++ b/pkg/native_stack_traces/testcases/convert/regress_262474517_trace_2.txt
@@ -0,0 +1,6 @@
+Non-fatal Exception: io.flutter.plugins.firebase.crashlytics.FlutterError: Bad state: No element. Error thrown null.
+BuildId: c3126a4381294e13185549e5e94a4db9
+#00 abs 0 virt 000000000031ba6f _kDartIsolateSnapshotInstructions+0x14e87f
+#01 abs 0 virt 0000000000472017 _kDartIsolateSnapshotInstructions+0x2a4e27
+#02 abs 0 virt 00000000006bb31b _kDartIsolateSnapshotInstructions+0x4ee12b
+#03 abs 0 virt 00000000006451b7 _kDartIsolateSnapshotInstructions+0x477fc7