diff --git a/Makefile.in b/Makefile.in
index a375471..83c5ecb 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -804,7 +804,7 @@ BASE_FLAGS_TO_PASS = \
 	"STAGE1_LANGUAGES=$(STAGE1_LANGUAGES)" \
 	"GNATBIND=$(GNATBIND)" \
 	"GNATMAKE=$(GNATMAKE)" \
-	"GDC=$(GDC)" \
+	"`echo 'GDC=$(GDC)' | sed -e 's/-idirafter [^ ]*//g'`" \
 	"GDCFLAGS=$(GDCFLAGS)" \
 	"AR_FOR_TARGET=$(AR_FOR_TARGET)" \
 	"AS_FOR_TARGET=$(AS_FOR_TARGET)" \
@@ -817,7 +817,7 @@ BASE_FLAGS_TO_PASS = \
 	"GFORTRAN_FOR_TARGET=$(GFORTRAN_FOR_TARGET)" \
 	"GOC_FOR_TARGET=$(GOC_FOR_TARGET)" \
 	"GOCFLAGS_FOR_TARGET=$(GOCFLAGS_FOR_TARGET)" \
-	"GDC_FOR_TARGET=$(GDC_FOR_TARGET)" \
+	"`echo 'GDC_FOR_TARGET=$(GDC_FOR_TARGET)' | sed -e 's/-idirafter [^ ]*//g'`" \
 	"GDCFLAGS_FOR_TARGET=$(GDCFLAGS_FOR_TARGET)" \
 	"LD_FOR_TARGET=$(LD_FOR_TARGET)" \
 	"LIPO_FOR_TARGET=$(LIPO_FOR_TARGET)" \
@@ -890,7 +890,7 @@ EXTRA_HOST_FLAGS = \
 	'DLLTOOL=$(DLLTOOL)' \
 	'GFORTRAN=$(GFORTRAN)' \
 	'GOC=$(GOC)' \
-	'GDC=$(GDC)' \
+	"`echo 'GDC=$(GDC)' | sed -e 's/-idirafter [^ ]*//g'`" \
 	'LD=$(LD)' \
 	'LIPO=$(LIPO)' \
 	'NM=$(NM)' \
@@ -966,8 +966,11 @@ EXTRA_TARGET_FLAGS = \
 	'STAGE1_LDFLAGS=$$(POSTSTAGE1_LDFLAGS)' \
 	'STAGE1_LIBS=$$(POSTSTAGE1_LIBS)' \
 	"TFLAGS=$$TFLAGS"
+EXTRA_TARGET_FLAGS_D = \
+	"`echo $(EXTRA_TARGET_FLAGS) | sed -e 's/-idirafter [^ ]*//g'`"
 
 TARGET_FLAGS_TO_PASS = $(BASE_FLAGS_TO_PASS) $(EXTRA_TARGET_FLAGS)
+TARGET_FLAGS_TO_PASS_D = $(BASE_FLAGS_TO_PASS) $(EXTRA_TARGET_FLAGS_D)
 
 # Flags to pass down to gcc.  gcc builds a library, libgcc.a, so it
 # unfortunately needs the native compiler and the target ar and
@@ -47285,7 +47288,7 @@ check-target-libphobos:
 	s=`cd $(srcdir); ${PWD_COMMAND}`; export s; \
 	$(NORMAL_TARGET_EXPORTS) \
 	(cd $(TARGET_SUBDIR)/libphobos && \
-	  $(MAKE) $(TARGET_FLAGS_TO_PASS)   check)
+	  $(MAKE) $(TARGET_FLAGS_TO_PASS_D)   check)
 
 @endif target-libphobos
 
@@ -47300,7 +47303,7 @@ install-target-libphobos: installdirs
 	s=`cd $(srcdir); ${PWD_COMMAND}`; export s; \
 	$(NORMAL_TARGET_EXPORTS) \
 	(cd $(TARGET_SUBDIR)/libphobos && \
-	  $(MAKE) $(TARGET_FLAGS_TO_PASS)  install)
+	  $(MAKE) $(TARGET_FLAGS_TO_PASS_D)  install)
 
 @endif target-libphobos
 
@@ -47315,7 +47318,7 @@ install-strip-target-libphobos: installdirs
 	s=`cd $(srcdir); ${PWD_COMMAND}`; export s; \
 	$(NORMAL_TARGET_EXPORTS) \
 	(cd $(TARGET_SUBDIR)/libphobos && \
-	  $(MAKE) $(TARGET_FLAGS_TO_PASS)  install-strip)
+	  $(MAKE) $(TARGET_FLAGS_TO_PASS_D)  install-strip)
 
 @endif target-libphobos
 
diff --git a/Makefile.tpl b/Makefile.tpl
index 41cae58..b3d32e7 100644
--- a/Makefile.tpl
+++ b/Makefile.tpl
@@ -721,8 +721,11 @@ EXTRA_TARGET_FLAGS = \
 	'STAGE1_LDFLAGS=$$(POSTSTAGE1_LDFLAGS)' \
 	'STAGE1_LIBS=$$(POSTSTAGE1_LIBS)' \
 	"TFLAGS=$$TFLAGS"
+EXTRA_TARGET_FLAGS_D = \
+	"`echo $(EXTRA_TARGET_FLAGS) | sed -e 's/-idirafter [^ ]*//g'`"
 
 TARGET_FLAGS_TO_PASS = $(BASE_FLAGS_TO_PASS) $(EXTRA_TARGET_FLAGS)
+TARGET_FLAGS_TO_PASS_D = $(BASE_FLAGS_TO_PASS) $(EXTRA_TARGET_FLAGS_D)
 
 # Flags to pass down to gcc.  gcc builds a library, libgcc.a, so it
 # unfortunately needs the native compiler and the target ar and
diff --git a/libphobos/Makefile.in b/libphobos/Makefile.in
index e894417..2d18dcb 100644
--- a/libphobos/Makefile.in
+++ b/libphobos/Makefile.in
@@ -365,6 +365,7 @@ AM_MAKEFLAGS = \
 	"LIBCFLAGS=$(LIBCFLAGS)" \
 	"LIBCFLAGS_FOR_TARGET=$(LIBCFLAGS_FOR_TARGET)" \
 	"MAKE=$(MAKE)" \
+	"`echo 'MAKEFLAGS=$(MAKEFLAGS)' | sed -e 's/-j[0-9]+/-j1/'`" \
 	"MAKEINFO=$(MAKEINFO) $(MAKEINFOFLAGS)" \
 	"PICFLAG=$(PICFLAG)" \
 	"PICFLAG_FOR_TARGET=$(PICFLAG_FOR_TARGET)" \
@@ -694,6 +695,8 @@ uninstall-am:
 
 .PRECIOUS: Makefile
 
+.NOTPARALLEL:
+
 # GNU Make needs to see an explicit $(MAKE) variable in the command it
 # runs to enable its job server during parallel builds.  Hence the
 # comments below.
diff --git a/libphobos/configure b/libphobos/configure
index b3cb5f3..25adf2b 100755
--- a/libphobos/configure
+++ b/libphobos/configure
@@ -5122,6 +5122,7 @@ ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
 ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
 ac_compiler_gnu=$ac_cv_c_compiler_gnu
 
+GDC=`$as_echo "$GDC" | sed -e 's/-idirafter [^ ]*//g'`
 
 ac_ext=d
 ac_compile='$GDC -c $GDCFLAGS conftest.$ac_ext >&5'