diff -ru rxvt-unicode-9.22.orig/src/Makefile.in rxvt-unicode-9.22/src/Makefile.in
--- rxvt-unicode-9.22.orig/src/Makefile.in	2016-01-23 21:09:22.000000000 +0100
+++ rxvt-unicode-9.22/src/Makefile.in	2023-03-30 18:57:07.555416723 +0200
@@ -21,8 +21,8 @@
 LDFLAGS = @LDFLAGS@
 DEFS = @DEFS@
 LIBS = @LIBS@
-XINC = @X_CFLAGS@ @PIXBUF_CFLAGS@ @STARTUP_NOTIFICATION_CFLAGS@
-XLIB = @X_LIBS@ -lX11 @X_EXTRA_LIBS@ @PIXBUF_LIBS@ @STARTUP_NOTIFICATION_LIBS@
+XINC = @PIXBUF_CFLAGS@ @STARTUP_NOTIFICATION_CFLAGS@
+XLIB = -lX11 -lXmu @X_EXTRA_LIBS@ @PIXBUF_LIBS@ @STARTUP_NOTIFICATION_LIBS@
 COMPILE = $(CXX) -I.. -I$(srcdir) -I. -I$(srcdir)/../libev -I$(srcdir)/../libptytty/src $(DEFS) $(CPPFLAGS) $(CXXFLAGS) $(XINC)
 LINK = @LINKER@ $(LDFLAGS)
 EXEEXT = @EXEEXT@