diff --git a/llvm/lib/ProfileData/InstrProfReader.cpp b/llvm/lib/ProfileData/InstrProfReader.cpp
index a95d9bc3b08a..f923ad2ddd9c 100644
--- a/llvm/lib/ProfileData/InstrProfReader.cpp
+++ b/llvm/lib/ProfileData/InstrProfReader.cpp
@@ -90,14 +90,14 @@ RawInstrProfReader::RawInstrProfReader(std::unique_ptr<MemoryBuffer> DataBuffer)
 
 static uint64_t getRawMagic() {
   return
-    uint64_t('l') << 56 |
-    uint64_t('p') << 48 |
-    uint64_t('r') << 40 |
-    uint64_t('o') << 32 |
-    uint64_t('f') << 24 |
-    uint64_t('r') << 16 |
-    uint64_t('a') <<  8 |
-    uint64_t('w');
+    uint64_t(255) << 56 |
+    uint64_t('l') << 48 |
+    uint64_t('p') << 40 |
+    uint64_t('r') << 32 |
+    uint64_t('o') << 24 |
+    uint64_t('f') << 16 |
+    uint64_t('r') <<  8 |
+    uint64_t(129);
 }
 
 bool RawInstrProfReader::hasFormat(const MemoryBuffer &DataBuffer) {
diff --git a/llvm/test/tools/llvm-profdata/Inputs/binary.profdata b/llvm/test/tools/llvm-profdata/Inputs/binary.profdata
index 156c483d15f1..e8cef21de5f2 100644
Binary files a/llvm/test/tools/llvm-profdata/Inputs/binary.profdata and b/llvm/test/tools/llvm-profdata/Inputs/binary.profdata differ
diff --git a/llvm/test/tools/llvm-profdata/raw-magic-but-no-header.test b/llvm/test/tools/llvm-profdata/raw-magic-but-no-header.test
index e899ece2755e..6db723c3e253 100644
--- a/llvm/test/tools/llvm-profdata/raw-magic-but-no-header.test
+++ b/llvm/test/tools/llvm-profdata/raw-magic-but-no-header.test
@@ -1,6 +1,6 @@
-RUN: printf "warforpl" > %t
+RUN: printf '\201rforpl\377' > %t
 RUN: not llvm-profdata show %t 2>&1 | FileCheck %s
-RUN: printf "lprofraw" > %t
+RUN: printf '\377lprofr\201' > %t
 RUN: not llvm-profdata show %t 2>&1 | FileCheck %s
 
 CHECK: error: {{.+}}: Invalid header