diff --git a/ndk/platforms/android-12/include/unistd.h b/ndk/platforms/android-12/include/unistd.h
index d92549fb3..d1fe5c78d 100644
--- a/ndk/platforms/android-12/include/unistd.h
+++ b/ndk/platforms/android-12/include/unistd.h
@@ -180,7 +180,7 @@ static __inline__ int __getpageshift(void) {
   return __page_shift;
 }
 
-extern int sysconf(int  name);
+long sysconf(int);
 
 extern int daemon(int, int);
 
diff --git a/ndk/platforms/android-21/include/sys/sysconf.h b/ndk/platforms/android-21/include/sys/sysconf.h
index 0a46e7aab..1bdebc730 100644
--- a/ndk/platforms/android-21/include/sys/sysconf.h
+++ b/ndk/platforms/android-21/include/sys/sysconf.h
@@ -129,7 +129,7 @@ __BEGIN_DECLS
 #define _SC_AVPHYS_PAGES                0x0063
 #define _SC_MONOTONIC_CLOCK             0x0064
 
-extern int sysconf(int name);
+long sysconf(int name);
 
 __END_DECLS
 
diff --git a/ndk/platforms/android-21/include/unistd.h b/ndk/platforms/android-21/include/unistd.h
index 7fbafdf27..e108e6e3d 100644
--- a/ndk/platforms/android-21/include/unistd.h
+++ b/ndk/platforms/android-21/include/unistd.h
@@ -177,7 +177,7 @@ extern int  acct(const char*  filepath);
 
 int getpagesize(void);
 
-extern int sysconf(int  name);
+long sysconf(int);
 
 extern int daemon(int, int);
 
diff --git a/ndk/platforms/android-3/include/sys/sysconf.h b/ndk/platforms/android-3/include/sys/sysconf.h
index 0a46e7aab..1bdebc730 100644
--- a/ndk/platforms/android-3/include/sys/sysconf.h
+++ b/ndk/platforms/android-3/include/sys/sysconf.h
@@ -129,7 +129,7 @@ __BEGIN_DECLS
 #define _SC_AVPHYS_PAGES                0x0063
 #define _SC_MONOTONIC_CLOCK             0x0064
 
-extern int sysconf(int name);
+long sysconf(int name);
 
 __END_DECLS
 
diff --git a/ndk/platforms/android-3/include/unistd.h b/ndk/platforms/android-3/include/unistd.h
index 53088d4b5..7e1127257 100644
--- a/ndk/platforms/android-3/include/unistd.h
+++ b/ndk/platforms/android-3/include/unistd.h
@@ -168,7 +168,7 @@ static __inline__ int __getpageshift(void) {
   return __page_shift;
 }
 
-extern int sysconf(int  name);
+long sysconf(int);
 
 extern int daemon(int, int);
 
diff --git a/ndk/platforms/android-8/include/unistd.h b/ndk/platforms/android-8/include/unistd.h
index ab8aee278..b106fe6e9 100644
--- a/ndk/platforms/android-8/include/unistd.h
+++ b/ndk/platforms/android-8/include/unistd.h
@@ -173,7 +173,7 @@ static __inline__ int __getpageshift(void) {
   return __page_shift;
 }
 
-extern int sysconf(int  name);
+long sysconf(int);
 
 extern int daemon(int, int);
 
diff --git a/ndk/platforms/android-9/include/unistd.h b/ndk/platforms/android-9/include/unistd.h
index f92ec108a..86f352b25 100644
--- a/ndk/platforms/android-9/include/unistd.h
+++ b/ndk/platforms/android-9/include/unistd.h
@@ -177,7 +177,7 @@ static __inline__ int __getpageshift(void) {
   return __page_shift;
 }
 
-extern int sysconf(int  name);
+long sysconf(int);
 
 extern int daemon(int, int);