diff --git a/src/auto-reply/reply/block-streaming.test.ts b/src/auto-reply/reply/block-streaming.test.ts
index ad4d3ee936f..475b6dfcbf8 100644
--- a/src/auto-reply/reply/block-streaming.test.ts
+++ b/src/auto-reply/reply/block-streaming.test.ts
@@ -99,6 +99,52 @@ describe("resolveEffectiveBlockStreamingConfig", () => {
     ).toMatchObject({ minChars: 10, maxChars: 40, idleMs: 2 });
   });
 
+  it("merges partial account nested block coalescing over channel config", () => {
+    const cfg = {
+      channels: {
+        imessage: {
+          streaming: { block: { coalesce: { minChars: 25, maxChars: 80, idleMs: 5 } } },
+          accounts: {
+            personal: {
+              streaming: { block: { coalesce: { idleMs: 2 } } },
+            },
+          },
+        },
+      },
+    } as OpenClawConfig;
+
+    expect(
+      resolveEffectiveBlockStreamingConfig({
+        cfg,
+        provider: "imessage",
+        accountId: "personal",
+      }).coalescing,
+    ).toMatchObject({ minChars: 25, maxChars: 80, idleMs: 2 });
+  });
+
+  it("merges legacy account block coalescing over channel nested config", () => {
+    const cfg = {
+      channels: {
+        imessage: {
+          streaming: { block: { coalesce: { minChars: 25, maxChars: 80, idleMs: 5 } } },
+          accounts: {
+            personal: {
+              blockStreamingCoalesce: { idleMs: 2 },
+            },
+          },
+        },
+      },
+    } as OpenClawConfig;
+
+    expect(
+      resolveEffectiveBlockStreamingConfig({
+        cfg,
+        provider: "imessage",
+        accountId: "personal",
+      }).coalescing,
+    ).toMatchObject({ minChars: 25, maxChars: 80, idleMs: 2 });
+  });
+
   it("allows ACP maxChunkChars overrides above base defaults up to provider text limits", () => {
     const cfg = {
       channels: {
diff --git a/src/auto-reply/reply/block-streaming.ts b/src/auto-reply/reply/block-streaming.ts
index e2e05ba3fd8..ef0560130b4 100644
--- a/src/auto-reply/reply/block-streaming.ts
+++ b/src/auto-reply/reply/block-streaming.ts
@@ -39,6 +39,14 @@ type ProviderBlockStreamingConfig = {
   >;
 };
 
+function resolveScopedBlockStreamingCoalesce(
+  config: ProviderBlockStreamingConfig | undefined,
+): BlockStreamingCoalesceConfig | undefined {
+  return config
+    ? (resolveChannelStreamingBlockCoalesce(config) ?? config.blockStreamingCoalesce)
+    : undefined;
+}
+
 function resolveProviderBlockStreamingCoalesce(params: {
   cfg: OpenClawConfig | undefined;
   providerKey?: TextChunkProvider;
@@ -57,12 +65,12 @@ function resolveProviderBlockStreamingCoalesce(params: {
   const normalizedAccountId = normalizeAccountId(accountId);
   const typed = providerCfg as ProviderBlockStreamingConfig;
   const accountCfg = resolveAccountEntry(typed.accounts, normalizedAccountId);
-  return (
-    resolveChannelStreamingBlockCoalesce(accountCfg) ??
-    resolveChannelStreamingBlockCoalesce(typed) ??
-    accountCfg?.blockStreamingCoalesce ??
-    typed.blockStreamingCoalesce
-  );
+  const channelCoalesce = resolveScopedBlockStreamingCoalesce(typed);
+  const accountCoalesce = resolveScopedBlockStreamingCoalesce(accountCfg);
+  if (channelCoalesce || accountCoalesce) {
+    return { ...channelCoalesce, ...accountCoalesce };
+  }
+  return undefined;
 }
 
 export type BlockStreamingCoalescing = {