diff --git a/libs/binder/Parcel.cpp b/libs/binder/Parcel.cpp
index 1a4ede1..3773760 100644
--- a/libs/binder/Parcel.cpp
+++ b/libs/binder/Parcel.cpp
@@ -520,7 +520,7 @@
     }
 }
 
-#if defined(__ANDROID_VNDK__) && !defined(__ANDROID_APEX__)
+#if defined(__ANDROID_VNDK__)
 constexpr int32_t kHeader = B_PACK_CHARS('V', 'N', 'D', 'R');
 #else
 constexpr int32_t kHeader = B_PACK_CHARS('S', 'Y', 'S', 'T');
diff --git a/libs/binder/ProcessState.cpp b/libs/binder/ProcessState.cpp
index c38249e..edadcd5 100644
--- a/libs/binder/ProcessState.cpp
+++ b/libs/binder/ProcessState.cpp
@@ -406,12 +406,6 @@
     , mThreadPoolSeq(1)
     , mCallRestriction(CallRestriction::NONE)
 {
-
-// TODO(b/166468760): enforce in build system
-#if defined(__ANDROID_APEX__)
-    LOG_ALWAYS_FATAL("Cannot use libbinder in APEX (only system.img libbinder) since it is not stable.");
-#endif
-
     if (mDriverFD >= 0) {
         // mmap the binder, providing a chunk of virtual address space to receive transactions.
         mVMStart = mmap(nullptr, BINDER_VM_SIZE, PROT_READ, MAP_PRIVATE | MAP_NORESERVE, mDriverFD, 0);
diff --git a/libs/binder/Stability.cpp b/libs/binder/Stability.cpp
index 339c538..b56e09f 100644
--- a/libs/binder/Stability.cpp
+++ b/libs/binder/Stability.cpp
@@ -76,18 +76,12 @@
 }
 
 Stability::Level Stability::getLocalLevel() {
+#ifdef __ANDROID_APEX__
+#error APEX can't use libbinder (must use libbinder_ndk)
+#endif
+
 #ifdef __ANDROID_VNDK__
-    #ifdef __ANDROID_APEX__
-        // TODO(b/142684679) avoid use_vendor on system APEXes
-        #if !defined(__ANDROID_APEX_COM_ANDROID_MEDIA_SWCODEC__) \
-            && !defined(__ANDROID_APEX_TEST_COM_ANDROID_MEDIA_SWCODEC__)
-        #error VNDK + APEX only defined for com.android.media.swcodec
-        #endif
-        // TODO(b/142684679) avoid use_vendor on system APEXes
-        return Level::SYSTEM;
-    #else
-        return Level::VENDOR;
-    #endif
+    return Level::VENDOR;
 #else
     // TODO(b/139325195): split up stability levels for system/APEX.
     return Level::SYSTEM;
diff --git a/libs/binder/ndk/include_platform/android/binder_stability.h b/libs/binder/ndk/include_platform/android/binder_stability.h
index f5e8bf6..44ed48f 100644
--- a/libs/binder/ndk/include_platform/android/binder_stability.h
+++ b/libs/binder/ndk/include_platform/android/binder_stability.h
@@ -30,6 +30,8 @@
     FLAG_PRIVATE_VENDOR = 0x10000000,
 };
 
+// TODO(b/180646847): __ANDROID_APEX__ here is what allows product partition to
+// talk to system.
 #if defined(__ANDROID_VNDK__) && !defined(__ANDROID_APEX__)
 
 enum {