--- src/3rdparty/javascriptcore/JavaScriptCore/wtf/Platform.h
+++ src/3rdparty/javascriptcore/JavaScriptCore/wtf/Platform.h
@@ -405,7 +405,7 @@
 #endif
 
 /* OS(FREEBSD) - FreeBSD */
-#ifdef __FreeBSD__
+#if defined (__FreeBSD__) || defined (__DragonFly__)
 #define WTF_OS_FREEBSD 1
 #endif
 
--- src/3rdparty/webkit/Source/WebKit/qt/Api/qwebpage.cpp
+++ src/3rdparty/webkit/Source/WebKit/qt/Api/qwebpage.cpp
@@ -3781,6 +3781,8 @@ QString QWebPage::userAgentForUrl(const QUrl&) const
 
 #elif defined Q_OS_BSD4
         firstPartTemp += QString::fromLatin1("BSD Four");
+#elif defined Q_OS_DRAGONFLY
+        firstPartTemp += QString::fromLatin1("DragonFly");
 #elif defined Q_OS_FREEBSD
         firstPartTemp += QString::fromLatin1("FreeBSD");
 #elif defined Q_OS_HPUX
--- src/core/global/qglobal.h
+++ src/core/global/qglobal.h
@@ -178,6 +178,10 @@ QT_USE_NAMESPACE
 #elif defined(__linux__) || defined(__linux)
 #  define Q_OS_LINUX
 
+#elif defined(__DragonFly__)
+#  define Q_OS_DRAGONFLY
+#  define Q_OS_BSD4
+
 #elif defined(__FreeBSD__)
 #  define Q_OS_FREEBSD
 #  define Q_OS_BSD4
@@ -1665,7 +1669,7 @@ Q_CORE_EXPORT int qrand();
 
 
 #if defined (__ELF__)
-#  if defined (Q_OS_LINUX) || defined (Q_OS_SOLARIS) || defined (Q_OS_FREEBSD) || defined (Q_OS_OPENBSD)
+#  if defined (Q_OS_LINUX) || defined (Q_OS_SOLARIS) || defined (Q_OS_FREEBSD) || defined (Q_OS_OPENBSD) || defined (Q_OS_DRAGONFLY)
 #    define Q_OF_ELF
 #  endif
 #endif
--- src/core/global/qplatformdefs.h
+++ src/core/global/qplatformdefs.h
@@ -280,7 +280,7 @@ typedef enum {
 
 
 // ***********
-#elif defined(Q_OS_FREEBSD) || defined(Q_OS_NETBSD)
+#elif defined(Q_OS_FREEBSD) || defined(Q_OS_NETBSD) || defined(Q_OS_DRAGONFLY)
 
 #include <qplatformposix.h>