diff --git a/libc/private/ErrnoRestorer.h b/libc/private/ErrnoRestorer.h
index f467393..52e115a 100644
--- a/libc/private/ErrnoRestorer.h
+++ b/libc/private/ErrnoRestorer.h
@@ -14,8 +14,7 @@
  * limitations under the License.
  */
 
-#ifndef ERRNO_RESTORER_H
-#define ERRNO_RESTORER_H
+#pragma once
 
 #include <errno.h>
 
@@ -37,7 +36,5 @@
  private:
   int saved_errno_;
 
-  DISALLOW_COPY_AND_ASSIGN(ErrnoRestorer);
+  BIONIC_DISALLOW_COPY_AND_ASSIGN(ErrnoRestorer);
 };
-
-#endif // ERRNO_RESTORER_H
diff --git a/libc/private/KernelArgumentBlock.h b/libc/private/KernelArgumentBlock.h
index e05ceb9..886dd32 100644
--- a/libc/private/KernelArgumentBlock.h
+++ b/libc/private/KernelArgumentBlock.h
@@ -14,8 +14,7 @@
  * limitations under the License.
  */
 
-#ifndef KERNEL_ARGUMENT_BLOCK_H
-#define KERNEL_ARGUMENT_BLOCK_H
+#pragma once
 
 #include <elf.h>
 #include <link.h>
@@ -71,7 +70,5 @@
   libc_shared_globals* shared_globals;
 
  private:
-  DISALLOW_COPY_AND_ASSIGN(KernelArgumentBlock);
+  BIONIC_DISALLOW_COPY_AND_ASSIGN(KernelArgumentBlock);
 };
-
-#endif // KERNEL_ARGUMENT_BLOCK_H
diff --git a/libc/private/ScopedPthreadMutexLocker.h b/libc/private/ScopedPthreadMutexLocker.h
index 58462e3..1c1e4a7 100644
--- a/libc/private/ScopedPthreadMutexLocker.h
+++ b/libc/private/ScopedPthreadMutexLocker.h
@@ -14,8 +14,7 @@
  * limitations under the License.
  */
 
-#ifndef SCOPED_PTHREAD_MUTEX_LOCKER_H
-#define SCOPED_PTHREAD_MUTEX_LOCKER_H
+#pragma once
 
 #include <pthread.h>
 
@@ -34,7 +33,5 @@
  private:
   pthread_mutex_t* mu_;
 
-  DISALLOW_IMPLICIT_CONSTRUCTORS(ScopedPthreadMutexLocker);
+  BIONIC_DISALLOW_IMPLICIT_CONSTRUCTORS(ScopedPthreadMutexLocker);
 };
-
-#endif // SCOPED_PTHREAD_MUTEX_LOCKER_H
diff --git a/libc/private/ScopedReaddir.h b/libc/private/ScopedReaddir.h
index 1a59e1a..dc22309 100644
--- a/libc/private/ScopedReaddir.h
+++ b/libc/private/ScopedReaddir.h
@@ -14,8 +14,7 @@
  * limitations under the License.
  */
 
-#ifndef SCOPED_READDIR_H
-#define SCOPED_READDIR_H
+#pragma once
 
 #include <dirent.h>
 
@@ -47,7 +46,5 @@
  private:
   DIR* dir_;
 
-  DISALLOW_COPY_AND_ASSIGN(ScopedReaddir);
+  BIONIC_DISALLOW_COPY_AND_ASSIGN(ScopedReaddir);
 };
-
-#endif // SCOPED_READDIR_H
diff --git a/libc/private/ScopedSignalBlocker.h b/libc/private/ScopedSignalBlocker.h
index d1cf629..10aacb3 100644
--- a/libc/private/ScopedSignalBlocker.h
+++ b/libc/private/ScopedSignalBlocker.h
@@ -46,5 +46,5 @@
 
   sigset64_t old_set_;
 
-  DISALLOW_COPY_AND_ASSIGN(ScopedSignalBlocker);
+  BIONIC_DISALLOW_COPY_AND_ASSIGN(ScopedSignalBlocker);
 };
diff --git a/libc/private/WriteProtected.h b/libc/private/WriteProtected.h
index 7a6b098..69a6822 100644
--- a/libc/private/WriteProtected.h
+++ b/libc/private/WriteProtected.h
@@ -14,8 +14,7 @@
  * limitations under the License.
  */
 
-#ifndef _PRIVATE_WRITEPROTECTED_H
-#define _PRIVATE_WRITEPROTECTED_H
+#pragma once
 
 #include <errno.h>
 #include <string.h>
@@ -33,7 +32,7 @@
   char padding[PAGE_SIZE];
 
   WriteProtectedContents() = default;
-  DISALLOW_COPY_AND_ASSIGN(WriteProtectedContents);
+  BIONIC_DISALLOW_COPY_AND_ASSIGN(WriteProtectedContents);
 } __attribute__((aligned(PAGE_SIZE)));
 
 // Write protected wrapper class that aligns its contents to a page boundary,
@@ -49,7 +48,7 @@
 
  public:
   WriteProtected() = default;
-  DISALLOW_COPY_AND_ASSIGN(WriteProtected);
+  BIONIC_DISALLOW_COPY_AND_ASSIGN(WriteProtected);
 
   void initialize() {
     // Not strictly necessary, but this will hopefully segfault if we initialize
@@ -82,5 +81,3 @@
     }
   }
 };
-
-#endif
diff --git a/libc/private/bionic_lock.h b/libc/private/bionic_lock.h
index 54168d3..eebfeff 100644
--- a/libc/private/bionic_lock.h
+++ b/libc/private/bionic_lock.h
@@ -25,8 +25,8 @@
  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
-#ifndef _BIONIC_LOCK_H
-#define _BIONIC_LOCK_H
+
+#pragma once
 
 #include <stdatomic.h>
 #include "private/bionic_futex.h"
@@ -85,10 +85,8 @@
     lock_.unlock();
   }
 
-  DISALLOW_COPY_AND_ASSIGN(LockGuard);
+  BIONIC_DISALLOW_COPY_AND_ASSIGN(LockGuard);
 
  private:
   Lock& lock_;
 };
-
-#endif  // _BIONIC_LOCK_H
diff --git a/libc/private/bionic_macros.h b/libc/private/bionic_macros.h
index 0a36cdb..4800e3a 100644
--- a/libc/private/bionic_macros.h
+++ b/libc/private/bionic_macros.h
@@ -14,31 +14,17 @@
  * limitations under the License.
  */
 
-#ifndef _BIONIC_MACROS_H_
-#define _BIONIC_MACROS_H_
+#pragma once
 
 #include <stdint.h>
 
-// Frameworks OpenGL code currently leaks this header and allows
-// collisions with other declarations, e.g., from libnativehelper.
-// TODO: Remove once cleaned up. b/18334516
-#if !defined(DISALLOW_COPY_AND_ASSIGN)
-// DISALLOW_COPY_AND_ASSIGN disallows the copy and operator= functions.
-// It goes in the private: declarations in a class.
-#define DISALLOW_COPY_AND_ASSIGN(TypeName) \
-  TypeName(const TypeName&) = delete;      \
+#define BIONIC_DISALLOW_COPY_AND_ASSIGN(TypeName) \
+  TypeName(const TypeName&) = delete;             \
   void operator=(const TypeName&) = delete
-#endif  // !defined(DISALLOW_COPY_AND_ASSIGN)
 
-// A macro to disallow all the implicit constructors, namely the
-// default constructor, copy constructor and operator= functions.
-//
-// This should be used in the private: declarations for a class
-// that wants to prevent anyone from instantiating it. This is
-// especially useful for classes containing only static methods.
-#define DISALLOW_IMPLICIT_CONSTRUCTORS(TypeName) \
-  TypeName() = delete;                           \
-  DISALLOW_COPY_AND_ASSIGN(TypeName)
+#define BIONIC_DISALLOW_IMPLICIT_CONSTRUCTORS(TypeName) \
+  TypeName() = delete;                                  \
+  BIONIC_DISALLOW_COPY_AND_ASSIGN(TypeName)
 
 #define BIONIC_ROUND_UP_POWER_OF_2(value) \
   ((sizeof(value) == 8) \
@@ -101,5 +87,3 @@
 #else
 #define __BIONIC_FALLTHROUGH
 #endif
-
-#endif // _BIONIC_MACROS_H_
diff --git a/libc/private/bionic_systrace.h b/libc/private/bionic_systrace.h
index 304fb80..86d2a08 100644
--- a/libc/private/bionic_systrace.h
+++ b/libc/private/bionic_systrace.h
@@ -14,8 +14,7 @@
  * limitations under the License.
  */
 
-#ifndef BIONIC_SYSTRACE_H
-#define BIONIC_SYSTRACE_H
+#pragma once
 
 #include "bionic_macros.h"
 
@@ -31,10 +30,8 @@
   void End();
  private:
   bool called_end_;
-  DISALLOW_COPY_AND_ASSIGN(ScopedTrace);
+  BIONIC_DISALLOW_COPY_AND_ASSIGN(ScopedTrace);
 };
 
 void bionic_trace_begin(const char* message);
 void bionic_trace_end();
-
-#endif