diff --git a/packages/opencode/src/config/config.ts b/packages/opencode/src/config/config.ts
index 261731b8b0a4..53ffaba81c00 100644
--- a/packages/opencode/src/config/config.ts
+++ b/packages/opencode/src/config/config.ts
@@ -1184,6 +1184,7 @@ export namespace Config {
             .optional()
             .describe("Tools that should only be available to primary agents."),
           continue_loop_on_deny: z.boolean().optional().describe("Continue the agent loop when a tool call is denied"),
+          context_compaction_threshold: z.number().min(10).max(100).optional().describe("Percentage of usable context space at which to trigger compaction (10-100)"),
           mcp_timeout: z
             .number()
             .int()
diff --git a/packages/opencode/src/session/compaction.ts b/packages/opencode/src/session/compaction.ts
index 9245426057c1..e1879197489f 100644
--- a/packages/opencode/src/session/compaction.ts
+++ b/packages/opencode/src/session/compaction.ts
@@ -5,6 +5,7 @@ import { Identifier } from "../id/id"
 import { Instance } from "../project/instance"
 import { Provider } from "../provider/provider"
 import { MessageV2 } from "./message-v2"
+import { Config } from "../config/config"
 import z from "zod"
 import { Token } from "../util/token"
 import { Log } from "../util/log"
@@ -12,7 +13,6 @@ import { SessionProcessor } from "./processor"
 import { fn } from "@/util/fn"
 import { Agent } from "@/agent/agent"
 import { Plugin } from "@/plugin"
-import { Config } from "@/config/config"
 import { ProviderTransform } from "@/provider/transform"
 
 export namespace SessionCompaction {
@@ -44,7 +44,13 @@ export namespace SessionCompaction {
     const usable = input.model.limit.input
       ? input.model.limit.input - reserved
       : context - ProviderTransform.maxOutputTokens(input.model)
-    return count >= usable
+
+    const threshold = config.experimental?.context_compaction_threshold ?? 100
+    const thresholdMultiplier = threshold / 100
+    const thresholdedUsable = usable * thresholdMultiplier
+
+    log.debug("Checking overflow", { count, usable, thresholdedUsable, threshold })
+    return count >= thresholdedUsable
   }
 
   export const PRUNE_MINIMUM = 20_000