diff --git a/src/halfutils.h b/src/halfutils.h
index 2ce0155..66ad23d 100644
--- a/src/halfutils.h
+++ b/src/halfutils.h
@@ -1,9 +1,15 @@
 #ifndef HALFUTILS_H
 #define HALFUTILS_H
 
+#include <math.h>
+
 #include "common/shortest_dec.h"
 #include "halfvec.h"
 
+#ifdef F16C_SUPPORT
+#include <immintrin.h>
+#endif
+
 extern float (*HalfvecL2SquaredDistance) (int dim, half * ax, half * bx);
 extern float (*HalfvecInnerProduct) (int dim, half * ax, half * bx);
 
diff --git a/src/halfvec.c b/src/halfvec.c
index decc1a2..2c1108b 100644
--- a/src/halfvec.c
+++ b/src/halfvec.c
@@ -23,10 +23,6 @@
 #define TYPALIGN_INT 'i'
 #endif
 
-#ifdef F16C_SUPPORT
-#include <immintrin.h>
-#endif
-
 /*
  * Get a half from a message buffer
  */