diff --git a/x11-wm/blackbox/Makefile b/x11-wm/blackbox/Makefile
index c592ae897c78..a62ccf5a846d 100644
--- a/x11-wm/blackbox/Makefile
+++ b/x11-wm/blackbox/Makefile
@@ -23,6 +23,7 @@ GNU_CONFIGURE=	yes
 USE_REINPLACE=	yes
 
 pre-patch:
+	${REINPLACE_CMD} -e 's#-pedantic##' ${WRKSRC}/configure
 	${REINPLACE_CMD} -e 's#nls src util#nls src#' ${WRKSRC}/Makefile.in
 	${REINPLACE_CMD} -E 's/^SUBDIRS/#SUBDIRS/' ${WRKSRC}/doc/Makefile.in
 	${REINPLACE_CMD} -e 's# bsetroot.1 bsetbg.1##' ${WRKSRC}/doc/Makefile.in
diff --git a/x11-wm/blackbox/files/patch-src::Window.cc b/x11-wm/blackbox/files/patch-src::Window.cc
new file mode 100644
index 000000000000..ec6c3afd4e04
--- /dev/null
+++ b/x11-wm/blackbox/files/patch-src::Window.cc
@@ -0,0 +1,10 @@
+--- src/Window.cc.orig Wed Aug 13 12:40:02 2003 
++++ src/Window.cc      Wed Aug 13 12:41:03 2003
+@@ -44,6 +44,8 @@
+ #endif // HAVE_STDLIB_H
+ }
++#include <cassert>
++
+ #include "i18n.hh"
+ #include "blackbox.hh"
+ #include "GCCache.hh"