Index: include/cmath
===================================================================
--- include/cmath
+++ include/cmath
@@ -306,6 +306,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
+#ifndef __FreeBSD__
 using ::signbit;
 using ::fpclassify;
 using ::isfinite;
@@ -319,13 +320,14 @@
 using ::islessgreater;
 using ::isunordered;
 using ::isunordered;
+#endif // __FreeBSD__
 
 using ::float_t;
 using ::double_t;
 
-#ifndef _AIX
+#if !defined(_AIX) && !defined(__FreeBSD__)
 using ::abs;
-#endif
+#endif // !AIX && !__FreeBSD__
 
 #ifndef __sun__
 using ::acos;