diff --git a/clang/lib/Headers/avx2intrin.h b/clang/lib/Headers/avx2intrin.h
index 63b1efc10537..1887fc80e630 100644
--- a/clang/lib/Headers/avx2intrin.h
+++ b/clang/lib/Headers/avx2intrin.h
@@ -25,6 +25,9 @@
 #error "Never use <avx2intrin.h> directly; include <immintrin.h> instead."
 #endif
 
+#ifndef __AVX2INTRIN_H
+#define __AVX2INTRIN_H
+
 /* SSE4 Multiple Packed Sums of Absolute Difference.  */
 #define _mm256_mpsadbw_epu8(X, Y, M) __builtin_ia32_mpsadbw256((X), (Y), (M))
 
@@ -1199,3 +1202,5 @@ _mm_srlv_epi64(__m128i __X, __m128i __Y)
   (__m256i)__builtin_ia32_gatherq_q256((__v4di)_mm256_setzero_si256(), \
              (const __v4di *)__m, (__v4di)__i, \
              (__v4di)_mm256_set1_epi64x(-1), (s)); })
+
+#endif /* __AVX2INTRIN_H */
diff --git a/clang/lib/Headers/avxintrin.h b/clang/lib/Headers/avxintrin.h
index 0683a65facc9..f522ac72f243 100644
--- a/clang/lib/Headers/avxintrin.h
+++ b/clang/lib/Headers/avxintrin.h
@@ -25,6 +25,9 @@
 #error "Never use <avxintrin.h> directly; include <immintrin.h> instead."
 #endif
 
+#ifndef __AVXINTRIN_H
+#define __AVXINTRIN_H
+
 typedef double __v4df __attribute__ ((__vector_size__ (32)));
 typedef float __v8sf __attribute__ ((__vector_size__ (32)));
 typedef long long __v4di __attribute__ ((__vector_size__ (32)));
@@ -1220,3 +1223,5 @@ _mm256_storeu2_m128i(__m128i *__addr_hi, __m128i *__addr_lo, __m256i __a)
   __v128 = _mm256_extractf128_si256(__a, 1);
   __builtin_ia32_storedqu((char *)__addr_hi, (__v16qi)__v128);
 }
+
+#endif /* __AVXINTRIN_H */
diff --git a/clang/lib/Headers/rdseedintrin.h b/clang/lib/Headers/rdseedintrin.h
index 54aabd177a1d..0fef1fa49680 100644
--- a/clang/lib/Headers/rdseedintrin.h
+++ b/clang/lib/Headers/rdseedintrin.h
@@ -25,6 +25,9 @@
 #error "Never use <rdseedintrin.h> directly; include <x86intrin.h> instead."
 #endif
 
+#ifndef __RDSEEDINTRIN_H
+#define __RDSEEDINTRIN_H
+
 #ifdef __RDSEED__
 static __inline__ int __attribute__((__always_inline__, __nodebug__))
 _rdseed16_step(unsigned short *__p)
@@ -46,3 +49,4 @@ _rdseed64_step(unsigned long long *__p)
 }
 #endif
 #endif /* __RDSEED__ */
+#endif /* __RDSEEDINTRIN_H */
diff --git a/clang/lib/Headers/rtmintrin.h b/clang/lib/Headers/rtmintrin.h
index bdc2b994264f..26149ca8522d 100644
--- a/clang/lib/Headers/rtmintrin.h
+++ b/clang/lib/Headers/rtmintrin.h
@@ -25,6 +25,9 @@
 #error "Never use <rtmintrin.h> directly; include <immintrin.h> instead."
 #endif
 
+#ifndef __RTMINTRIN_H
+#define __RTMINTRIN_H
+
 #define _XBEGIN_STARTED   (~0u)
 #define _XABORT_EXPLICIT  (1 << 0)
 #define _XABORT_RETRY     (1 << 1)
@@ -47,3 +50,5 @@ _xend(void)
 }
 
 #define _xabort(imm) __builtin_ia32_xabort((imm))
+
+#endif /* __RTMINTRIN_H */