diff --git a/liblog/include/log/log_read.h b/liblog/include/log/log_read.h
index f3be0b877..e2bc29721 100644
--- a/liblog/include/log/log_read.h
+++ b/liblog/include/log/log_read.h
@@ -16,22 +16,8 @@
 
 #pragma once
 
-#include <sys/types.h>
-
-/* deal with possible sys/cdefs.h conflict with fcntl.h */
-#ifdef __unused
-#define __unused_defined __unused
-#undef __unused
-#endif
-
-#include <fcntl.h> /* Pick up O_* macros */
-
-/* restore definitions from above */
-#ifdef __unused_defined
-#define __unused __attribute__((__unused__))
-#endif
-
 #include <stdint.h>
+#include <sys/types.h>
 
 #include <log/log_id.h>
 #include <log/log_time.h>
@@ -40,6 +26,8 @@
 extern "C" {
 #endif
 
+#define ANDROID_LOG_WRAP_DEFAULT_TIMEOUT 7200 /* 2 hour default */
+
 /*
  * Native log reading interface section. See logcat for sample code.
  *
@@ -114,13 +102,10 @@ ssize_t android_logger_get_prune_list(struct logger_list* logger_list,
                                       char* buf, size_t len);
 int android_logger_set_prune_list(struct logger_list* logger_list, const char* buf, size_t len);
 
-#ifndef O_NONBLOCK
+/* The below values are used for the `mode` argument of the below functions. */
+/* Note that 0x00000003 were previously used and should be considered reserved. */
 #define ANDROID_LOG_NONBLOCK 0x00000800
-#else
-#define ANDROID_LOG_NONBLOCK O_NONBLOCK
-#endif
 #define ANDROID_LOG_WRAP 0x40000000 /* Block until buffer about to wrap */
-#define ANDROID_LOG_WRAP_DEFAULT_TIMEOUT 7200 /* 2 hour default */
 #define ANDROID_LOG_PSTORE 0x80000000
 
 struct logger_list* android_logger_list_alloc(int mode, unsigned int tail,
diff --git a/liblog/include_vndk/log/log.h b/liblog/include_vndk/log/log.h
index a79beecd4..ab4adc49a 100644
--- a/liblog/include_vndk/log/log.h
+++ b/liblog/include_vndk/log/log.h
@@ -3,6 +3,9 @@
 #ifndef _LIBS_LOG_LOG_H
 #define _LIBS_LOG_LOG_H
 
+/* Historically vendors have depended on this header being included. */
+#include <fcntl.h>
+
 #include <android/log.h>
 #include <log/log_id.h>
 #include <log/log_main.h>