diff --git a/include/boost/config/platform/bsd.hpp b/include/boost/config/platform/bsd.hpp
index 810d3707..f02b0e26 100644
--- a/include/boost/config/platform/bsd.hpp
+++ b/include/boost/config/platform/bsd.hpp
@@ -36,7 +36,8 @@
 // FreeBSD 3.x has pthreads support, but defines _POSIX_THREADS in <pthread.h>
 // and not in <unistd.h>
 //
-#if (defined(__FreeBSD__) && (__FreeBSD__ <= 3)) || defined(__OpenBSD__)
+#if (defined(__FreeBSD__) && (__FreeBSD__ <= 3))\
+   || defined(__OpenBSD__) || defined(__DragonFly__) 
 #  define BOOST_HAS_PTHREADS
 #endif
 
@@ -55,13 +56,13 @@
 #endif
 
 #if !((defined(__FreeBSD__) && (__FreeBSD__ >= 5)) \
-      || (__NetBSD_GCC__ >= 2095003))
+      || (__NetBSD_GCC__ >= 2095003) || defined(__DragonFly__))
 #  define BOOST_NO_CWCHAR
 #endif
 //
 // The BSD <ctype.h> has macros only, no functions:
 //
-#if !defined(__OpenBSD__)
+#if !defined(__OpenBSD__) || defined(__DragonFly__)
 #  define BOOST_NO_CTYPE_FUNCTIONS
 #endif
 
diff --git a/include/boost/config/suffix.hpp b/include/boost/config/suffix.hpp
index f71c644f..142e8e00 100644
--- a/include/boost/config/suffix.hpp
+++ b/include/boost/config/suffix.hpp
@@ -223,7 +223,8 @@
 // from here then add to the appropriate compiler section):
 //
 #if (defined(__MT__) || defined(_MT) || defined(_REENTRANT) \
-    || defined(_PTHREADS)) && !defined(BOOST_HAS_THREADS)
+    || defined(_PTHREADS) || defined(__APPLE__) || defined(__DragonFly__)) \
+    && !defined(BOOST_HAS_THREADS)
 #  define BOOST_HAS_THREADS
 #endif