diff --git a/src/features/context-injector/collector.test.ts b/src/features/context-injector/collector.test.ts
index 695ff4af8..4001b5483 100644
--- a/src/features/context-injector/collector.test.ts
+++ b/src/features/context-injector/collector.test.ts
@@ -205,6 +205,45 @@ describe("ContextCollector", () => {
       const ids = pending.entries.map((e) => e.id)
       expect(ids).toEqual(["first", "second", "third"])
     })
+
+    it("keeps registration order even when Date.now values are not monotonic", () => {
+      // given
+      const sessionID = "ses_order_non_monotonic_time"
+      const originalDateNow = Date.now
+      const mockedTimestamps = [300, 100, 200]
+      let timestampIndex = 0
+      Date.now = () => mockedTimestamps[timestampIndex++] ?? 0
+
+      try {
+        collector.register(sessionID, {
+          id: "first",
+          source: "custom",
+          content: "First",
+          priority: "normal",
+        })
+        collector.register(sessionID, {
+          id: "second",
+          source: "custom",
+          content: "Second",
+          priority: "normal",
+        })
+        collector.register(sessionID, {
+          id: "third",
+          source: "custom",
+          content: "Third",
+          priority: "normal",
+        })
+      } finally {
+        Date.now = originalDateNow
+      }
+
+      // when
+      const pending = collector.getPending(sessionID)
+
+      // then
+      const ids = pending.entries.map((entry) => entry.id)
+      expect(ids).toEqual(["first", "second", "third"])
+    })
   })
 
   describe("consume", () => {
diff --git a/src/features/context-injector/collector.ts b/src/features/context-injector/collector.ts
index af60e4196..f1b9f61ab 100644
--- a/src/features/context-injector/collector.ts
+++ b/src/features/context-injector/collector.ts
@@ -14,6 +14,8 @@ const PRIORITY_ORDER: Record<ContextPriority, number> = {
 
 const CONTEXT_SEPARATOR = "\n\n---\n\n"
 
+let registrationCounter = 0
+
 export class ContextCollector {
   private sessions: Map<string, Map<string, ContextEntry>> = new Map()
 
@@ -30,7 +32,7 @@ export class ContextCollector {
       source: options.source,
       content: options.content,
       priority: options.priority ?? "normal",
-      timestamp: Date.now(),
+      registrationOrder: ++registrationCounter,
       metadata: options.metadata,
     }
 
@@ -77,7 +79,7 @@ export class ContextCollector {
     return entries.sort((a, b) => {
       const priorityDiff = PRIORITY_ORDER[a.priority] - PRIORITY_ORDER[b.priority]
       if (priorityDiff !== 0) return priorityDiff
-      return a.timestamp - b.timestamp
+      return a.registrationOrder - b.registrationOrder
     })
   }
 }
diff --git a/src/features/context-injector/types.ts b/src/features/context-injector/types.ts
index c203be981..23030d0e9 100644
--- a/src/features/context-injector/types.ts
+++ b/src/features/context-injector/types.ts
@@ -27,8 +27,8 @@ export interface ContextEntry {
   content: string
   /** Priority for ordering (default: normal) */
   priority: ContextPriority
-  /** Timestamp when registered */
-  timestamp: number
+  /** Monotonic order when registered */
+  registrationOrder: number
   /** Optional metadata for debugging/logging */
   metadata?: Record<string, unknown>
 }