diff --git a/x11/qt4/Makefile b/x11/qt4/Makefile
index f0e8e6ed694..ae9199b432a 100644
--- a/x11/qt4/Makefile
+++ b/x11/qt4/Makefile
@@ -1,4 +1,4 @@
-# $OpenBSD: Makefile,v 1.151 2018/01/20 14:03:39 jsg Exp $
+# $OpenBSD: Makefile,v 1.152 2018/04/16 08:07:35 pvk Exp $
 
 USE_WXNEEDED =		Yes # QtWebKit
 
@@ -25,13 +25,13 @@ PKGNAME-main =		qt4-${PKGVERSION}
 PKGNAME-debug =		qt4-debug-${PKGVERSION}
 FULLPKGNAME-html =	qt4-html-${PKGVERSION}
 FULLPKGPATH-html =	${BASE_PKGPATH},-html
-REVISION-main =		14
-REVISION-mysql =	2
-REVISION-postgresql =	2
-REVISION-sqlite2 =	2
-REVISION-tds =		2
-REVISION-debug =	1
-REVISION-examples =	3
+REVISION-main =		15
+REVISION-mysql =	3
+REVISION-postgresql =	3
+REVISION-sqlite2 =	3
+REVISION-tds =		3
+REVISION-debug =	2
+REVISION-examples =	4
 REVISION-html =		0
 
 # XXX qmake include parser is bogus
@@ -119,7 +119,6 @@ CONFIGURE_ARGS +=	-I${LOCALBASE}/include/mysql -L${LOCALBASE}/lib/mysql \
 CONFIGURE_ARGS +=	-I${LOCALBASE}/include/postgresql \
 			-I${LOCALBASE}/include/postgresql/server \
 			-plugin-sql-psql
-CONFIGURE_ARGS +=	-platform openbsd-g++4
 
 # XXX make sure those libraries gets written to libQtGui.la
 QMAKE_LIBS_GUI =	freetype SM ICE Xi Xrender Xinerama fontconfig Xext X11
@@ -242,8 +241,16 @@ MAKE_FLAGS +=	LIB$l_VERSION=$v
 
 DESTDIRNAME =	INSTALL_ROOT
 
+.include <bsd.port.arch.mk>
+.if ${PROPERTIES:Mclang}
+CONFIGURE_ARGS +=	-platform openbsd-clang
+.else
+CONFIGURE_ARGS +=	-platform openbsd-g++4
+.endif
+
 pre-patch:
 	cd ${WRKDIST} && cp -R mkspecs/openbsd-g++ mkspecs/openbsd-g++4
+	cd ${WRKDIST} && cp -R mkspecs/openbsd-g++ mkspecs/openbsd-clang
 
 post-build:
 .for l v in ${SHARED_LIBS}
diff --git a/x11/qt4/patches/patch-mkspecs_openbsd-clang_qmake_conf b/x11/qt4/patches/patch-mkspecs_openbsd-clang_qmake_conf
new file mode 100644
index 00000000000..682e606039b
--- /dev/null
+++ b/x11/qt4/patches/patch-mkspecs_openbsd-clang_qmake_conf
@@ -0,0 +1,77 @@
+$OpenBSD: patch-mkspecs_openbsd-clang_qmake_conf,v 1.1 2018/04/16 08:07:35 pvk Exp $
+
+Index: mkspecs/openbsd-clang/qmake.conf
+--- mkspecs/openbsd-clang/qmake.conf.orig
++++ mkspecs/openbsd-clang/qmake.conf
+@@ -8,47 +8,48 @@ TEMPLATE		= app
+ CONFIG			+= qt warn_on release link_prl gdb_dwarf_index
+ QT			+= core gui
+ 
+-QMAKE_CC		= gcc
++QMAKE_OPENBSD_SHLIBS    = 1
++QMAKE_CC		= cc
+ QMAKE_LEX		= flex
+ QMAKE_LEXFLAGS		=
+ QMAKE_YACC		= yacc
+ QMAKE_YACCFLAGS		= -d
+-QMAKE_CFLAGS		= -pipe
++QMAKE_CFLAGS		= -pipe -O2 -fno-wrapv $(COPTS)
+ QMAKE_CFLAGS_DEPS	= -M
+ QMAKE_CFLAGS_WARN_ON	= -Wall -W
+ QMAKE_CFLAGS_WARN_OFF	= -w
+-QMAKE_CFLAGS_RELEASE	= -O2
++QMAKE_CFLAGS_RELEASE	= -O2 -fno-wrapv $(COPTS)
+ QMAKE_CFLAGS_DEBUG	= -g
+ QMAKE_CFLAGS_SHLIB	= -fPIC
+ QMAKE_CFLAGS_STATIC_LIB	= $$QMAKE_CFLAGS_SHLIB
+ QMAKE_CFLAGS_YACC	= -Wno-unused -Wno-parentheses
+ QMAKE_CFLAGS_THREAD	= -pthread
+ 
+-QMAKE_CXX		= g++
+-QMAKE_CXXFLAGS		= $$QMAKE_CFLAGS
++QMAKE_CXX		= c++
++QMAKE_CXXFLAGS		= -std=c++03 $$QMAKE_CFLAGS
+ QMAKE_CXXFLAGS_DEPS	= $$QMAKE_CFLAGS_DEPS
+ QMAKE_CXXFLAGS_WARN_ON	= $$QMAKE_CFLAGS_WARN_ON
+ QMAKE_CXXFLAGS_WARN_OFF	= $$QMAKE_CFLAGS_WARN_OFF
+-QMAKE_CXXFLAGS_RELEASE	= $$QMAKE_CFLAGS_RELEASE
++QMAKE_CXXFLAGS_RELEASE	= -std=c++03 $$QMAKE_CFLAGS_RELEASE
+ QMAKE_CXXFLAGS_DEBUG	= $$QMAKE_CFLAGS_DEBUG
+ QMAKE_CXXFLAGS_SHLIB	= $$QMAKE_CFLAGS_SHLIB
+ QMAKE_CXXFLAGS_STATIC_LIB = $$QMAKE_CFLAGS_STATIC_LIB
+ QMAKE_CXXFLAGS_YACC	= $$QMAKE_CFLAGS_YACC
+ QMAKE_CXXFLAGS_THREAD	= $$QMAKE_CFLAGS_THREAD
+ 
+-QMAKE_INCDIR		= /usr/local/include
+-QMAKE_LIBDIR		= /usr/local/lib
+-QMAKE_INCDIR_X11	= /usr/X11R6/include
+-QMAKE_LIBDIR_X11	= /usr/X11R6/lib
++QMAKE_INCDIR		= $(LOCALBASE)/include
++QMAKE_LIBDIR		= $(LOCALBASE)/lib
++QMAKE_INCDIR_X11	= $(X11BASE)/include
++QMAKE_LIBDIR_X11	= $(X11BASE)/lib
+ QMAKE_INCDIR_QT		= $$[QT_INSTALL_HEADERS]
+ QMAKE_LIBDIR_QT		= $$[QT_INSTALL_LIBS]
+ QMAKE_INCDIR_OPENGL	= /usr/X11R6/include
+ QMAKE_LIBDIR_OPENGL	= /usr/X11R6/lib
+ 
+-QMAKE_LINK		= g++
+-QMAKE_LINK_SHLIB	= g++
+-QMAKE_LINK_C		= gcc
+-QMAKE_LINK_C_SHLIB	= gcc
++QMAKE_LINK		= c++
++QMAKE_LINK_SHLIB	= c++
++QMAKE_LINK_C		= cc
++QMAKE_LINK_C_SHLIB	= cc
+ QMAKE_LINK_SHLIB_CMD	= $$QMAKE_LINK_SHLIB $(LFLAGS) \
+ 	$$QMAKE_CFLAGS_SHLIB $$QMAKE_LFLAGS \
+ 	-o $(TARGETD) $(OBJECTS) $(OBJMOC) $(LIBS)
+@@ -57,7 +58,7 @@ QMAKE_LFLAGS_RELEASE	=
+ QMAKE_LFLAGS_DEBUG	=
+ QMAKE_LFLAGS_SHLIB	= -shared
+ QMAKE_LFLAGS_PLUGIN	= $$QMAKE_LFLAGS_SHLIB
+-QMAKE_LFLAGS_SONAME	= -Wl,-soname,
++QMAKE_LFLAGS_SONAME	= 
+ QMAKE_LFLAGS_THREAD	= -pthread
+ QMAKE_LFLAGS_NOUNDEF	= -Wl,-no_unresolved
+ 
diff --git a/x11/qt4/patches/patch-mkspecs_openbsd-clang_qplatformdefs_h b/x11/qt4/patches/patch-mkspecs_openbsd-clang_qplatformdefs_h
new file mode 100644
index 00000000000..fcabddc68d4
--- /dev/null
+++ b/x11/qt4/patches/patch-mkspecs_openbsd-clang_qplatformdefs_h
@@ -0,0 +1,11 @@
+$OpenBSD: patch-mkspecs_openbsd-clang_qplatformdefs_h,v 1.1 2018/04/16 08:07:35 pvk Exp $
+
+Index: mkspecs/openbsd-clang/qplatformdefs.h
+--- mkspecs/openbsd-clang/qplatformdefs.h.orig
++++ mkspecs/openbsd-clang/qplatformdefs.h
+@@ -108,4 +108,5 @@
+ #define QT_AOUT_UNDERSCORE
+ #endif
+ 
++#define QT_GCC4_ATOMICS
+ #endif // QPLATFORMDEFS_H
diff --git a/x11/qt4/pkg/PLIST-main b/x11/qt4/pkg/PLIST-main
index 7449a4c8d94..674c812a1d9 100644
--- a/x11/qt4/pkg/PLIST-main
+++ b/x11/qt4/pkg/PLIST-main
@@ -1,4 +1,4 @@
-@comment $OpenBSD: PLIST-main,v 1.35 2015/09/16 07:13:02 dcoppa Exp $
+@comment $OpenBSD: PLIST-main,v 1.36 2018/04/16 08:07:35 pvk Exp $
 @pkgpath x11/qt4
 @pkgpath x11/qt4,-phonon
 @pkgpath x11/qt4,-sqlite
@@ -3621,6 +3621,11 @@ lib/qt4/mkspecs/modules/qt_webkit_version.pri
 lib/qt4/mkspecs/netbsd-g++/
 lib/qt4/mkspecs/netbsd-g++/qmake.conf
 lib/qt4/mkspecs/netbsd-g++/qplatformdefs.h
+lib/qt4/mkspecs/openbsd-clang/
+lib/qt4/mkspecs/openbsd-clang/qmake.conf
+@comment lib/qt4/mkspecs/openbsd-clang/qmake.conf.orig
+lib/qt4/mkspecs/openbsd-clang/qplatformdefs.h
+@comment lib/qt4/mkspecs/openbsd-clang/qplatformdefs.h.orig
 lib/qt4/mkspecs/openbsd-g++/
 lib/qt4/mkspecs/openbsd-g++/qmake.conf
 @comment lib/qt4/mkspecs/openbsd-g++/qmake.conf.orig