diff --git a/src/__support/CMakeLists.txt b/src/__support/CMakeLists.txt
index 980b510..32f538e 100644
--- a/src/__support/CMakeLists.txt
+++ b/src/__support/CMakeLists.txt
@@ -2,4 +2,5 @@
   common
   HDRS
     common.h
+    sanitizer_annotations.h
 )
diff --git a/utils/FPUtil/CMakeLists.txt b/utils/FPUtil/CMakeLists.txt
index 2c1c166..43ee643 100644
--- a/utils/FPUtil/CMakeLists.txt
+++ b/utils/FPUtil/CMakeLists.txt
@@ -31,6 +31,7 @@
     libc.include.math
     libc.include.errno
     libc.include.fenv
+    libc.src.__support.common
     libc.utils.CPP.standalone_cpp
 )
 
diff --git a/utils/FPUtil/x86_64/FEnv.h b/utils/FPUtil/x86_64/FEnv.h
index 3fb4881..1196aba 100644
--- a/utils/FPUtil/x86_64/FEnv.h
+++ b/utils/FPUtil/x86_64/FEnv.h
@@ -12,6 +12,8 @@
 #include <fenv.h>
 #include <stdint.h>
 
+#include "src/__support/sanitizer_annotations.h"
+
 namespace __llvm_libc {
 namespace fputil {
 
@@ -95,6 +97,7 @@
 static inline uint16_t getX87ControlWord() {
   uint16_t w;
   __asm__ __volatile__("fnstcw %0" : "=m"(w)::);
+  SANITIZER_MEMORY_INITIALIZED(&w, sizeof(w));
   return w;
 }
 
@@ -105,6 +108,7 @@
 static inline uint16_t getX87StatusWord() {
   uint16_t w;
   __asm__ __volatile__("fnstsw %0" : "=m"(w)::);
+  SANITIZER_MEMORY_INITIALIZED(&w, sizeof(w));
   return w;
 }
 
@@ -115,6 +119,7 @@
 static inline uint32_t getMXCSR() {
   uint32_t w;
   __asm__ __volatile__("stmxcsr %0" : "=m"(w)::);
+  SANITIZER_MEMORY_INITIALIZED(&w, sizeof(w));
   return w;
 }
 
@@ -124,6 +129,7 @@
 
 static inline void getX87StateDescriptor(X87StateDescriptor &s) {
   __asm__ __volatile__("fnstenv %0" : "=m"(s));
+  SANITIZER_MEMORY_INITIALIZED(&s, sizeof(s));
 }
 
 static inline void writeX87StateDescriptor(const X87StateDescriptor &s) {