diff --git a/pkg/dev_compiler/bin/dartdevc.dart b/pkg/dev_compiler/bin/dartdevc.dart
index 4d4ac46cbbf..a906e00ec51 100755
--- a/pkg/dev_compiler/bin/dartdevc.dart
+++ b/pkg/dev_compiler/bin/dartdevc.dart
@@ -56,7 +56,7 @@ class _CompilerWorker extends AsyncWorkerLoop {
     /// Build a map of uris to digests.
     final inputDigests = <Uri, List<int>>{};
     for (var input in request.inputs) {
-      inputDigests[Uri.base.resolve(input.path)] = input.digest;
+      inputDigests[sourcePathToUri(input.path)] = input.digest;
     }
 
     lastResult = await runZoned(
diff --git a/pkg/dev_compiler/lib/src/compiler/shared_command.dart b/pkg/dev_compiler/lib/src/compiler/shared_command.dart
index 9c05758da81..d2ff5b70e69 100644
--- a/pkg/dev_compiler/lib/src/compiler/shared_command.dart
+++ b/pkg/dev_compiler/lib/src/compiler/shared_command.dart
@@ -369,7 +369,7 @@ Map placeSourceMap(Map sourceMap, String sourceMapPath,
     }
 
     // Convert to a local file path if it's not.
-    sourcePath = path.absolute(path.fromUri(uri));
+    sourcePath = sourcePathToUri(path.absolute(path.fromUri(uri))).path;
 
     // Allow bazel mappings to override.
     var match = bazelMappings[sourcePath];
diff --git a/pkg/front_end/lib/src/api_unstable/ddc.dart b/pkg/front_end/lib/src/api_unstable/ddc.dart
index 0bb81548b55..6785a843db2 100644
--- a/pkg/front_end/lib/src/api_unstable/ddc.dart
+++ b/pkg/front_end/lib/src/api_unstable/ddc.dart
@@ -150,7 +150,7 @@ Future<InitializedCompilerState> initializeIncrementalCompiler(
       oldState?.workerInputCache ?? new Map<Uri, WorkerInputComponent>();
   var sdkDigest = workerInputDigests[sdkSummary];
   if (sdkDigest == null) {
-    throw new StateError("Expected to get sdk digest at $cachedSdkInput");
+    throw new StateError("Expected to get sdk digest at $sdkSummary");
   }
 
   cachedSdkInput = workerInputCache[sdkSummary];
diff --git a/utils/bazel/kernel_worker.dart b/utils/bazel/kernel_worker.dart
index e8d91fca039..d13bb1a887c 100644
--- a/utils/bazel/kernel_worker.dart
+++ b/utils/bazel/kernel_worker.dart
@@ -372,5 +372,7 @@ class DevCompilerSummaryTarget extends DevCompilerTarget {
 
 Uri _toUri(String uriString) {
   if (uriString == null) return null;
-  return Uri.base.resolve(uriString);
+  // Windows-style paths use '\', so convert them to '/' in case they've been
+  // concatenated with Unix-style paths.
+  return Uri.base.resolve(uriString.replaceAll("\\", "/"));
 }