diff --git a/src/agent/runner.ts b/src/agent/runner.ts
index fd8305d..92b482c 100644
--- a/src/agent/runner.ts
+++ b/src/agent/runner.ts
@@ -879,7 +879,7 @@ export class AgentRunner {
     strategy: Extract<ContextStrategy, { type: 'compact' }>,
   ): LLMMessage[] {
     const estimated = estimateTokens(messages)
-    if (estimated <= strategy.maxTokens || messages.length < 4) {
+    if (estimated <= strategy.maxTokens) {
       return messages
     }
 
diff --git a/src/types.ts b/src/types.ts
index 765d9fe..e4f928b 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -70,18 +70,18 @@ export type ContextStrategy =
   | { type: 'sliding-window'; maxTurns: number }
   | { type: 'summarize'; maxTokens: number; summaryModel?: string }
   | {
-    type: 'compact'
-    /** Estimated token threshold that triggers compaction. Compaction is skipped when below this. */
-    maxTokens: number
-    /** Number of recent turn pairs (assistant+user) to keep intact. Default: 4. */
-    preserveRecentTurns?: number
-    /** Minimum chars in a tool_result content to qualify for compaction. Default: 200. */
-    minToolResultChars?: number
-    /** Minimum chars in an assistant text block to qualify for truncation. Default: 2000. */
-    minTextBlockChars?: number
-    /** Maximum chars to keep from a truncated text block (head excerpt). Default: 200. */
-    textBlockExcerptChars?: number
-  }
+      type: 'compact'
+      /** Estimated token threshold that triggers compaction. Compaction is skipped when below this. */
+      maxTokens: number
+      /** Number of recent turn pairs (assistant+user) to keep intact. Default: 4. */
+      preserveRecentTurns?: number
+      /** Minimum chars in a tool_result content to qualify for compaction. Default: 200. */
+      minToolResultChars?: number
+      /** Minimum chars in an assistant text block to qualify for truncation. Default: 2000. */
+      minTextBlockChars?: number
+      /** Maximum chars to keep from a truncated text block (head excerpt). Default: 200. */
+      textBlockExcerptChars?: number
+    }
   | {
     type: 'custom'
     compress: (