diff --git a/src/__tests__/perf/plugin-init-team-mode-resume-defer.test.ts b/src/__tests__/perf/plugin-init-team-mode-resume-defer.test.ts
index 8f5d490a4..646bbab37 100644
--- a/src/__tests__/perf/plugin-init-team-mode-resume-defer.test.ts
+++ b/src/__tests__/perf/plugin-init-team-mode-resume-defer.test.ts
@@ -16,11 +16,11 @@ function makeHangingClient(): {
     hangCount.value += 1
     return new Promise<never>(() => {})
   }
-  const client = {
+  const client = testCoerce<PluginInput["client"]>({
     session: {
       get: sessionGet,
     },
-  } as unknown as PluginInput["client"]
+  })
   return { hangCount, client }
 }
 
diff --git a/tests/hashline/test-edge-cases.ts b/tests/hashline/test-edge-cases.ts
index b00b0302d..4bf254908 100644
--- a/tests/hashline/test-edge-cases.ts
+++ b/tests/hashline/test-edge-cases.ts
@@ -459,7 +459,6 @@ const TEST_CASES: TestCase[] = [
       "Expected line 2 to be exactly 180 characters.",
     ].join(" "),
     validate: (content) => {
-      const expected = "L".repeat(180);
       const lines = content.replace(/\r/g, "").trimEnd().split("\n");
       if (!lines[1]) {
         return { passed: false, reason: "line 2 is missing" };
@@ -976,12 +975,12 @@ async function runTestCase(
     }
   }
 
-  const toolCalls = events.filter(
+  const toolCalls = testCoerce<ToolCallEvent[]>(events.filter(
     (e) => e.type === "tool_call"
-  ) as unknown as ToolCallEvent[];
-  const toolResults = events.filter(
+  ));
+  const toolResults = testCoerce<ToolResultEvent[]>(events.filter(
     (e) => e.type === "tool_result"
-  ) as unknown as ToolResultEvent[];
+  ));
 
   const editCalls = toolCalls.filter((e) => e.tool_name === "edit_file");
   const editCallIds = new Set(editCalls.map((e) => e.tool_call_id));
diff --git a/tests/hashline/test-edit-ops.ts b/tests/hashline/test-edit-ops.ts
index 05d63b4d2..599dc4851 100644
--- a/tests/hashline/test-edit-ops.ts
+++ b/tests/hashline/test-edit-ops.ts
@@ -45,7 +45,6 @@ const RESET = "\x1b[0m";
 const pass = (msg: string) => console.log(`  ${GREEN}✓${RESET} ${msg}`);
 const fail = (msg: string) => console.log(`  ${RED}✗${RESET} ${msg}`);
 const info = (msg: string) => console.log(`  ${DIM}${msg}${RESET}`);
-const warn = (msg: string) => console.log(`  ${YELLOW}⚠${RESET} ${msg}`);
 
 // ── Test case definition ─────────────────────────────────────
 interface TestCase {
@@ -669,12 +668,12 @@ async function runTestCase(
     }
   }
 
-  const toolCalls = events.filter(
+  const toolCalls = testCoerce<ToolCallEvent[]>(events.filter(
     (e) => e.type === "tool_call"
-  ) as unknown as ToolCallEvent[];
-  const toolResults = events.filter(
+  ));
+  const toolResults = testCoerce<ToolResultEvent[]>(events.filter(
     (e) => e.type === "tool_result"
-  ) as unknown as ToolResultEvent[];
+  ));
 
   const editCalls = toolCalls.filter((e) => e.tool_name === "edit_file");
   const editCallIds = new Set(editCalls.map((e) => e.tool_call_id));