--- a/configure.ac	2018-04-30 19:03:56.000000000 +0200
+++ a/configure.ac.new	2018-05-22 12:23:30.371174341 +0200
@@ -1946,11 +1946,11 @@
   MAGICK_LIBS=
 
   PKG_CHECK_EXISTS([$magick++], [
-    dnl Make sure we only get -I, -L, and -l flags.
+    dnl Make sure we only get -I, -D, -L, and -l flags.
     dnl Some Graphics/ImageMagick++ dnl packages add extra flags that are
     dnl useful when building Graphics/ImageMagick++ extentions.  These extra
     dnl flags break the Octave build.
-    MAGICK_CPPFLAGS="$($PKG_CONFIG --cflags-only-I $magick++ | $SED -e 's/^ *$//')"
+    MAGICK_CPPFLAGS=`$PKG_CONFIG --cflags $magick++ | sed -e 's/\(-@<:@DI@:>@@<:@^ \t@:>@*\)\|\(-@<:@^ \t@:>@*\)/\1/g'`
     MAGICK_LDFLAGS="$($PKG_CONFIG --libs-only-L $magick++ | $SED -e 's/^ *$//')"
     MAGICK_LIBS="$($PKG_CONFIG --libs-only-l $magick++ | $SED -e 's/^ *$//')"