diff --git a/scenarios/synapse.py b/scenarios/synapse.py
index 530aac1..9b70aab 100644
--- a/scenarios/synapse.py
+++ b/scenarios/synapse.py
@@ -6,7 +6,10 @@
 
 from scenarios.helpers import info, run_cmd, sh
 
-SYNAPSE_SDK_REPO = "https://github.com/FilOzone/synapse-sdk/"
+SYNAPSE_SDK_REPO = os.environ.get(
+    "SYNAPSE_SDK_REPO", "https://github.com/FilOzone/synapse-sdk/"
+)
+SYNAPSE_SDK_REF = os.environ.get("SYNAPSE_SDK_REF", "synapse-sdk-v1.0.1")
 
 
 def clone_and_build(tmp_dir: Path) -> Path | None:
@@ -17,7 +20,9 @@ def clone_and_build(tmp_dir: Path) -> Path | None:
     ):
         return None
     if not run_cmd(
-        ["git", "checkout", "master"], cwd=str(sdk_dir), label="checkout master HEAD"
+        ["git", "checkout", SYNAPSE_SDK_REF],
+        cwd=str(sdk_dir),
+        label=f"checkout {SYNAPSE_SDK_REF}",
     ):
         return None
     sdk_commit = sh(f"git -C {sdk_dir} rev-parse HEAD")
diff --git a/scenarios/test_multi_copy_upload.py b/scenarios/test_multi_copy_upload.py
index fd2b9d8..9763935 100644
--- a/scenarios/test_multi_copy_upload.py
+++ b/scenarios/test_multi_copy_upload.py
@@ -26,6 +26,7 @@
 RAND_FILE_NAME = "random_file"
 RAND_FILE_SIZE = 20 * 1024 * 1024
 RAND_FILE_SEED = 42
+FILECOIN_PIN_VERSION = "0.23.2"
 ADD_DEADLINE_SECS = 240
 ADD_INTERVAL_SECS = 10
 ADD_ATTEMPT_TIMEOUT_SECS = 180
@@ -74,17 +75,14 @@ def output_text(value) -> str:
 
 
 def patch_synapse_core_streaming_upload(npm_dir: Path) -> bool:
-    """Strip Content-Length from @filoz/synapse-core's streaming upload headers.
+    """Strip legacy Content-Length from @filoz/synapse-core streaming uploads.
 
-    synapse-core (as of 0.4.1, which filecoin-pin 0.20.1 resolves to) sets a
-    Content-Length header on a body that flows through a streaming Transform.
-    Node/undici rejects that as 'invalid content-length header', which
-    filecoin-pin surfaces as
+    Older synapse-core builds set a Content-Length header on a body that flows
+    through a streaming Transform. Node/undici rejects that as
+    'invalid content-length header', which filecoin-pin surfaces as
     'StorageContext store failed: Failed to store piece on service provider -
-    Network request failed'.
-
-    TODO: drop this patch once filecoin-pin pins a synapse-core release that
-    omits Content-Length on streaming bodies (track upstream in FilOzone/synapse-sdk).
+    Network request failed'. Newer builds only set Content-Length for the
+    non-streaming Blob fallback, so this helper is intentionally a no-op there.
 
     Returns True when the target file is in the desired state (whether or not
     a change was applied). Returns False only when the file is missing.
@@ -112,8 +110,8 @@ def patch_synapse_core_streaming_upload(npm_dir: Path) -> bool:
         )
     else:
         info(
-            "@filoz/synapse-core streaming upload already free of "
-            "Content-Length header; no patch needed"
+            "@filoz/synapse-core streaming upload has no legacy "
+            "Content-Length header pattern; no patch needed"
         )
     return True
 
@@ -246,7 +244,7 @@ def run():
                 "pkg",
                 "set",
                 "type=module",
-                "dependencies.filecoin-pin=0.20.1",
+                f"dependencies.filecoin-pin={FILECOIN_PIN_VERSION}",
                 "dependencies.multiformats=13.4.2",
             ],
             label="pin filecoin-pin dependencies",