diff --git a/libc/bionic/brk.cpp b/libc/bionic/brk.cpp
index a8c078b..e1a4b05 100644
--- a/libc/bionic/brk.cpp
+++ b/libc/bionic/brk.cpp
@@ -29,7 +29,7 @@
 #include <errno.h>
 #include <unistd.h>
 
-#if __LP64__
+#if defined(__LP64__)
 static void* __bionic_brk;
 #else
 void* __bionic_brk; // Accidentally exported by the NDK.
diff --git a/libc/bionic/fpclassify.cpp b/libc/bionic/fpclassify.cpp
index f8cea80..42ed3ef 100644
--- a/libc/bionic/fpclassify.cpp
+++ b/libc/bionic/fpclassify.cpp
@@ -113,7 +113,7 @@
 }
 __strong_alias(isnormalf, __isnormalf);
 
-#if __LP64__
+#if defined(__LP64__)
 
 // LP64 uses 128-bit long doubles.
 
diff --git a/libc/bionic/legacy_32_bit_support.cpp b/libc/bionic/legacy_32_bit_support.cpp
index f2bb37d..983fb32 100644
--- a/libc/bionic/legacy_32_bit_support.cpp
+++ b/libc/bionic/legacy_32_bit_support.cpp
@@ -37,7 +37,7 @@
 #include <sys/vfs.h>
 #include <unistd.h>
 
-#if __LP64__
+#if defined(__LP64__)
 #error This code is only needed on 32-bit systems!
 #endif
 
diff --git a/libc/bionic/open.cpp b/libc/bionic/open.cpp
index 41dce43..2daa21f 100644
--- a/libc/bionic/open.cpp
+++ b/libc/bionic/open.cpp
@@ -36,7 +36,7 @@
 extern "C" int __openat(int, const char*, int, int);
 
 static inline int force_O_LARGEFILE(int flags) {
-#if __LP64__
+#if defined(__LP64__)
   return flags; // No need, and aarch64's strace gets confused.
 #else
   return flags | O_LARGEFILE;
diff --git a/libc/bionic/pthread_create.cpp b/libc/bionic/pthread_create.cpp
index 58aa6f1..7986ada 100644
--- a/libc/bionic/pthread_create.cpp
+++ b/libc/bionic/pthread_create.cpp
@@ -101,7 +101,7 @@
     sched_param param;
     param.sched_priority = thread->attr.sched_priority;
     if (sched_setscheduler(thread->tid, thread->attr.sched_policy, &param) == -1) {
-#if __LP64__
+#if defined(__LP64__)
       // For backwards compatibility reasons, we only report failures on 64-bit devices.
       error = errno;
 #endif
diff --git a/libc/bionic/statvfs.cpp b/libc/bionic/statvfs.cpp
index 39ffb64..cd825eb 100644
--- a/libc/bionic/statvfs.cpp
+++ b/libc/bionic/statvfs.cpp
@@ -20,7 +20,7 @@
 
 // Paper over the fact that 32-bit kernels use fstatfs64/statfs64 with an extra argument,
 // but 64-bit kernels don't have the "64" bit suffix or the extra size_t argument.
-#if __LP64__
+#if defined(__LP64__)
 extern "C" int __fstatfs(int, struct statfs*);
 extern "C" int __statfs(const char*, struct statfs*);
 #  define __fstatfs64(fd,size,buf) __fstatfs(fd,buf)
diff --git a/libc/bionic/strtold.cpp b/libc/bionic/strtold.cpp
index 5616cf7..c55dd61 100644
--- a/libc/bionic/strtold.cpp
+++ b/libc/bionic/strtold.cpp
@@ -32,7 +32,7 @@
 extern "C" int __strtorQ(const char*, char**, int, void*);
 
 long double strtold(const char* s, char** end_ptr) {
-#if __LP64__
+#if defined(__LP64__)
   long double result;
   __strtorQ(s, end_ptr, FLT_ROUNDS, &result);
   return result;
diff --git a/libc/include/link.h b/libc/include/link.h
index f40e7e4..92ecceb 100644
--- a/libc/include/link.h
+++ b/libc/include/link.h
@@ -34,7 +34,7 @@
 
 __BEGIN_DECLS
 
-#if __LP64__
+#if defined(__LP64__)
 #define ElfW(type) Elf64_ ## type
 #else
 #define ElfW(type) Elf32_ ## type
diff --git a/libc/include/stdint.h b/libc/include/stdint.h
index 1cedca1..322a81c 100644
--- a/libc/include/stdint.h
+++ b/libc/include/stdint.h
@@ -39,7 +39,7 @@
 typedef unsigned short __uint16_t;
 typedef int __int32_t;
 typedef unsigned int __uint32_t;
-#if __LP64__
+#if defined(__LP64__)
 typedef long __int64_t;
 typedef unsigned long __uint64_t;
 #else
@@ -47,7 +47,7 @@
 typedef unsigned long long __uint64_t;
 #endif
 
-#if __LP64__
+#if defined(__LP64__)
 typedef long __intptr_t;
 typedef unsigned long __uintptr_t;
 #else
diff --git a/libc/include/sys/cdefs.h b/libc/include/sys/cdefs.h
index 13c3269..3b058e8 100644
--- a/libc/include/sys/cdefs.h
+++ b/libc/include/sys/cdefs.h
@@ -229,7 +229,7 @@
 #include <android/api-level.h>
 
 /* glibc compatibility. */
-#if __LP64__
+#if defined(__LP64__)
 #define __WORDSIZE 64
 #else
 #define __WORDSIZE 32
@@ -278,7 +278,7 @@
 #include <android/versioning.h>
 
 #if __has_builtin(__builtin_umul_overflow) || __GNUC__ >= 5
-#if __LP64__
+#if defined(__LP64__)
 #define __size_mul_overflow(a, b, result) __builtin_umull_overflow(a, b, result)
 #else
 #define __size_mul_overflow(a, b, result) __builtin_umul_overflow(a, b, result)
diff --git a/libc/private/bionic_ieee.h b/libc/private/bionic_ieee.h
index c579969..69095f0 100644
--- a/libc/private/bionic_ieee.h
+++ b/libc/private/bionic_ieee.h
@@ -79,7 +79,7 @@
   unsigned dbl_sign:1;
 };
 
-#if __LP64__
+#if defined(__LP64__)
 
 /* 64-bit Android uses ld128 long doubles. */
 
diff --git a/libc/upstream-openbsd/android/include/arith.h b/libc/upstream-openbsd/android/include/arith.h
index b262e4f..cb116d4 100644
--- a/libc/upstream-openbsd/android/include/arith.h
+++ b/libc/upstream-openbsd/android/include/arith.h
@@ -16,7 +16,7 @@
 
 #define IEEE_8087
 
-#if __LP64__
+#if defined(__LP64__)
 #define Long int
 #endif
 
diff --git a/libc/upstream-openbsd/android/include/gd_qnan.h b/libc/upstream-openbsd/android/include/gd_qnan.h
index e5bf973..bcdff28 100644
--- a/libc/upstream-openbsd/android/include/gd_qnan.h
+++ b/libc/upstream-openbsd/android/include/gd_qnan.h
@@ -23,7 +23,7 @@
 #define d_QNAN0 0x00000000
 #define d_QNAN1 0x7ff80000
 
-#if __LP64__
+#if defined(__LP64__)
 #define ld_QNAN0 0x00000000
 #define ld_QNAN1 0x00000000
 #define ld_QNAN2 0x00000000
diff --git a/tests/libc_logging_test.cpp b/tests/libc_logging_test.cpp
index d4ceded..4150483 100644
--- a/tests/libc_logging_test.cpp
+++ b/tests/libc_logging_test.cpp
@@ -133,7 +133,7 @@
 #if defined(__BIONIC__)
   char buf[BUFSIZ];
   __libc_format_buffer(buf, sizeof(buf), "%ld", LONG_MAX);
-#if __LP64__
+#if defined(__LP64__)
   EXPECT_STREQ("9223372036854775807", buf);
 #else
   EXPECT_STREQ("2147483647", buf);
@@ -147,7 +147,7 @@
 #if defined(__BIONIC__)
   char buf[BUFSIZ];
   __libc_format_buffer(buf, sizeof(buf), "%ld", LONG_MIN);
-#if __LP64__
+#if defined(__LP64__)
   EXPECT_STREQ("-9223372036854775808", buf);
 #else
   EXPECT_STREQ("-2147483648", buf);
diff --git a/tests/stdio_test.cpp b/tests/stdio_test.cpp
index 79c5e92..63da9e0 100644
--- a/tests/stdio_test.cpp
+++ b/tests/stdio_test.cpp
@@ -548,7 +548,7 @@
 TEST(STDIO_TEST, snprintf_ld_LONG_MAX) {
   char buf[BUFSIZ];
   snprintf(buf, sizeof(buf), "%ld", LONG_MAX);
-#if __LP64__
+#if defined(__LP64__)
   EXPECT_STREQ("9223372036854775807", buf);
 #else
   EXPECT_STREQ("2147483647", buf);
@@ -558,7 +558,7 @@
 TEST(STDIO_TEST, snprintf_ld_LONG_MIN) {
   char buf[BUFSIZ];
   snprintf(buf, sizeof(buf), "%ld", LONG_MIN);
-#if __LP64__
+#if defined(__LP64__)
   EXPECT_STREQ("-9223372036854775808", buf);
 #else
   EXPECT_STREQ("-2147483648", buf);
diff --git a/tests/sys_ptrace_test.cpp b/tests/sys_ptrace_test.cpp
index 9071acf..bdd6a89 100644
--- a/tests/sys_ptrace_test.cpp
+++ b/tests/sys_ptrace_test.cpp
@@ -183,7 +183,7 @@
   run_watchpoint_test_impl<uint8_t>(cpu);
   run_watchpoint_test_impl<uint16_t>(cpu);
   run_watchpoint_test_impl<uint32_t>(cpu);
-#if __LP64__
+#if defined(__LP64__)
   run_watchpoint_test_impl<uint64_t>(cpu);
 #endif
 }