diff --git a/libs/nativewindow/include/android/hardware_buffer.h b/libs/nativewindow/include/android/hardware_buffer.h
index 277560b..5c1b510 100644
--- a/libs/nativewindow/include/android/hardware_buffer.h
+++ b/libs/nativewindow/include/android/hardware_buffer.h
@@ -154,6 +154,8 @@
 
 typedef struct AHardwareBuffer AHardwareBuffer;
 
+#if __ANDROID_API__ >= 26
+
 /**
  * Allocates a buffer that backs an AHardwareBuffer using the passed
  * AHardwareBuffer_Desc.
@@ -246,6 +248,8 @@
  */
 int AHardwareBuffer_recvHandleFromUnixSocket(int socketFd, AHardwareBuffer** outBuffer) __INTRODUCED_IN(26);
 
+#endif // __ANDROID_API__ >= 26
+
 __END_DECLS
 
 #endif // ANDROID_HARDWARE_BUFFER_H
diff --git a/libs/nativewindow/include/android/native_window.h b/libs/nativewindow/include/android/native_window.h
index fd5d8b5..ba5295b 100644
--- a/libs/nativewindow/include/android/native_window.h
+++ b/libs/nativewindow/include/android/native_window.h
@@ -108,33 +108,33 @@
  * Acquire a reference on the given {@link ANativeWindow} object. This prevents the object
  * from being deleted until the reference is removed.
  */
-void ANativeWindow_acquire(ANativeWindow* window) __INTRODUCED_IN(26);
+void ANativeWindow_acquire(ANativeWindow* window);
 
 /**
  * Remove a reference that was previously acquired with {@link ANativeWindow_acquire()}.
  */
-void ANativeWindow_release(ANativeWindow* window) __INTRODUCED_IN(26);
+void ANativeWindow_release(ANativeWindow* window);
 
 /**
  * Return the current width in pixels of the window surface.
  *
  * \return negative value on error.
  */
-int32_t ANativeWindow_getWidth(ANativeWindow* window) __INTRODUCED_IN(26);
+int32_t ANativeWindow_getWidth(ANativeWindow* window);
 
 /**
  * Return the current height in pixels of the window surface.
  *
  * \return a negative value on error.
  */
-int32_t ANativeWindow_getHeight(ANativeWindow* window) __INTRODUCED_IN(26);
+int32_t ANativeWindow_getHeight(ANativeWindow* window);
 
 /**
  * Return the current pixel format (AHARDWAREBUFFER_FORMAT_*) of the window surface.
  *
  * \return a negative value on error.
  */
-int32_t ANativeWindow_getFormat(ANativeWindow* window) __INTRODUCED_IN(26);
+int32_t ANativeWindow_getFormat(ANativeWindow* window);
 
 /**
  * Change the format and size of the window buffers.
@@ -154,7 +154,7 @@
  * \return 0 for success, or a negative value on error.
  */
 int32_t ANativeWindow_setBuffersGeometry(ANativeWindow* window,
-        int32_t width, int32_t height, int32_t format) __INTRODUCED_IN(26);
+        int32_t width, int32_t height, int32_t format);
 
 /**
  * Lock the window's next drawing surface for writing.
@@ -167,7 +167,7 @@
  * \return 0 for success, or a negative value on error.
  */
 int32_t ANativeWindow_lock(ANativeWindow* window, ANativeWindow_Buffer* outBuffer,
-        ARect* inOutDirtyBounds) __INTRODUCED_IN(26);
+        ARect* inOutDirtyBounds);
 
 /**
  * Unlock the window's drawing surface after previously locking it,
@@ -175,7 +175,9 @@
  *
  * \return 0 for success, or a negative value on error.
  */
-int32_t ANativeWindow_unlockAndPost(ANativeWindow* window) __INTRODUCED_IN(26);
+int32_t ANativeWindow_unlockAndPost(ANativeWindow* window);
+
+#if __ANDROID_API__ >= 26
 
 /**
  * Set a transform that will be applied to future buffers posted to the window.
@@ -185,6 +187,8 @@
  */
 int32_t ANativeWindow_setBuffersTransform(ANativeWindow* window, int32_t transform) __INTRODUCED_IN(26);
 
+#endif // __ANDROID_API__ >= 26
+
 #ifdef __cplusplus
 };
 #endif