diff --git a/packages/poptart/CHANGELOG.md b/packages/poptart/CHANGELOG.md
index 213fa1f9b..0883c747a 100644
--- a/packages/poptart/CHANGELOG.md
+++ b/packages/poptart/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Release Note
 
+## v0.1.2
+
+- Require `poptart_xrpc` 0.1.1 for concrete binary request content types.
+
 ## v0.1.1
 
 - Bump `poptart_core` and `poptart_oauth` for opaque OAuth token restore support.
diff --git a/packages/poptart/pubspec.yaml b/packages/poptart/pubspec.yaml
index 0da1b25d9..ed052ea72 100644
--- a/packages/poptart/pubspec.yaml
+++ b/packages/poptart/pubspec.yaml
@@ -1,6 +1,6 @@
 name: poptart
 resolution: workspace
-version: 0.1.1
+version: 0.1.2
 description: Friendly Dart and Flutter SDK entrypoint for AT Protocol sessions, OAuth, XRPC, and core Poptart primitives.
 homepage: https://poptart.xyz
 documentation: https://poptart.xyz
@@ -14,7 +14,7 @@ dependencies:
   poptart_core: ^0.1.1
   poptart_oauth: ^0.1.1
   poptart_primitives: ^0.1.0
-  poptart_xrpc: ^0.1.0
+  poptart_xrpc: ^0.1.1
 
 topics:
   - atproto
diff --git a/packages/poptart_xrpc/CHANGELOG.md b/packages/poptart_xrpc/CHANGELOG.md
index dc98a0e80..88e004a99 100644
--- a/packages/poptart_xrpc/CHANGELOG.md
+++ b/packages/poptart_xrpc/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Release Note
 
+## v0.1.1
+
+- Ensure wildcard binary input encodings use a concrete request content type.
+
 ## v0.1.0
 
 - Initial Poptart fork release under the new `poptart_*` package name.
diff --git a/packages/poptart_xrpc/lib/src/xrpc/xrpc.dart b/packages/poptart_xrpc/lib/src/xrpc/xrpc.dart
index cafa26bc7..4325f85ca 100644
--- a/packages/poptart_xrpc/lib/src/xrpc/xrpc.dart
+++ b/packages/poptart_xrpc/lib/src/xrpc/xrpc.dart
@@ -486,10 +486,11 @@ Map<String, String> _appendContentType(
   final String? contentType,
 ) {
   if (body is Uint8List) {
-    return {
-      'Content-type':
-          contentType ?? lookupMimeType('', headerBytes: body) ?? '*/*',
-    }..addAll(headers ?? {});
+    final resolvedContentType = contentType == null || contentType.contains('*')
+        ? lookupMimeType('', headerBytes: body) ?? 'application/octet-stream'
+        : contentType;
+
+    return {'Content-type': resolvedContentType}..addAll(headers ?? {});
   }
 
   return {'Content-type': contentType ?? 'application/json'}
diff --git a/packages/poptart_xrpc/pubspec.yaml b/packages/poptart_xrpc/pubspec.yaml
index fe72fec2f..df48c6347 100644
--- a/packages/poptart_xrpc/pubspec.yaml
+++ b/packages/poptart_xrpc/pubspec.yaml
@@ -1,7 +1,7 @@
 name: poptart_xrpc
 resolution: workspace
 description: Core library for XRPC communication. This is a wrapped HTTP client for AT Protocol.
-version: 0.1.0
+version: 0.1.1
 homepage: https://poptart.xyz
 documentation: https://poptart.xyz
 repository: https://github.com/sprksocial/poptart
diff --git a/packages/poptart_xrpc/test/src/xrpc/xrpc_descriptor_test.dart b/packages/poptart_xrpc/test/src/xrpc/xrpc_descriptor_test.dart
index c0cab9bfd..9b33bf729 100644
--- a/packages/poptart_xrpc/test/src/xrpc/xrpc_descriptor_test.dart
+++ b/packages/poptart_xrpc/test/src/xrpc/xrpc_descriptor_test.dart
@@ -138,6 +138,67 @@ void main() {
       expect(response.data, const _ExampleObject(name: 'alice'));
     });
 
+    test(
+      'procedure call resolves wildcard input encoding from bytes',
+      () async {
+        final descriptor =
+            XRPCMethodDescriptor<void, Uint8List, _ExampleObject>(
+              nsid: NSID.parse('com.example.uploadBlob'),
+              kind: XRPCMethodKind.procedure,
+              inputEncoding: '*/*',
+              outputFromJson: _ExampleObject.fromJson,
+            );
+        final bytes = Uint8List.fromList([0xff, 0xd8, 0xff, 0xe0]);
+
+        final response = await call(
+          descriptor,
+          input: bytes,
+          postClient: (url, {body, encoding, headers}) async {
+            expect(body, bytes);
+            expect(headers, containsPair('Content-type', 'image/jpeg'));
+
+            return Response(
+              r'{"$type":"com.example.lexicon","name":"alice"}',
+              200,
+              request: Request('POST', url),
+            );
+          },
+        );
+
+        expect(response.data, const _ExampleObject(name: 'alice'));
+      },
+    );
+
+    test('procedure call falls back for unknown wildcard bytes', () async {
+      final descriptor = XRPCMethodDescriptor<void, Uint8List, _ExampleObject>(
+        nsid: NSID.parse('com.example.uploadBlob'),
+        kind: XRPCMethodKind.procedure,
+        inputEncoding: '*/*',
+        outputFromJson: _ExampleObject.fromJson,
+      );
+      final bytes = Uint8List.fromList([1, 2, 3]);
+
+      final response = await call(
+        descriptor,
+        input: bytes,
+        postClient: (url, {body, encoding, headers}) async {
+          expect(body, bytes);
+          expect(
+            headers,
+            containsPair('Content-type', 'application/octet-stream'),
+          );
+
+          return Response(
+            r'{"$type":"com.example.lexicon","name":"alice"}',
+            200,
+            request: Request('POST', url),
+          );
+        },
+      );
+
+      expect(response.data, const _ExampleObject(name: 'alice'));
+    });
+
     test('query call preserves descriptor bytes output', () async {
       final descriptor = XRPCMethodDescriptor<_ExampleParams, void, Uint8List>(
         nsid: NSID.parse('com.example.getBlob'),