diff --git a/lib/System/Mutex.cpp b/lib/System/Mutex.cpp
index 81dcd3b..f55dd3f 100644
--- a/lib/System/Mutex.cpp
+++ b/lib/System/Mutex.cpp
@@ -75,7 +75,7 @@
     errorcode = pthread_mutexattr_settype(&attr, kind);
     assert(errorcode == 0);
 
-#if !defined(__FreeBSD__) && !defined(__OpenBSD__) && !defined(__NetBSD__)
+#if !defined(__FreeBSD__) && !defined(__OpenBSD__) && !defined(__NetBSD__) && !defined(__DragonFly__)
     // Make it a process local mutex
     errorcode = pthread_mutexattr_setpshared(&attr, PTHREAD_PROCESS_PRIVATE);
 #endif
diff --git a/lib/Target/CBackend/CBackend.cpp b/lib/Target/CBackend/CBackend.cpp
index 2e9902d..71895f4 100644
--- a/lib/Target/CBackend/CBackend.cpp
+++ b/lib/Target/CBackend/CBackend.cpp
@@ -1415,7 +1415,7 @@
       << "extern void *__builtin_alloca(unsigned int);\n"
       << "#endif\n"
       << "#define alloca(x) __builtin_alloca(x)\n"
-      << "#elif defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__)\n"
+      << "#elif defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)\n"
       << "#define alloca(x) __builtin_alloca(x)\n"
       << "#elif defined(_MSC_VER)\n"
       << "#define inline _inline\n"