diff --git a/libsrc/geos/graph/Makefile b/libsrc/geos/graph/Makefile
index 9ea62b994..82b7cb123 100644
--- a/libsrc/geos/graph/Makefile
+++ b/libsrc/geos/graph/Makefile
@@ -11,7 +11,7 @@
 S_OBJS	= drawline.o drawpoint.o framerectangle.o hlineregs.o horizontalline.o\
 	  imprintrectangle.o invertline.o invertrectangle.o pointregs.o recoverline.o\
 	  recoverrectangle.o rectangle.o initdrawwindow.o setpattern.o testpoint.o verticalline.o\
-	  putchar.o putdecimal.o putstring.o usesystemfont.o\
+	  put_char.o putdecimal.o putstring.o usesystemfont.o\
 	  getcharwidth.o loadcharset.o bitmapup.o bitmapregs.o bitmapclip.o bitotherclip.o\
 	  graphicsstring.o getintcharint.o
 
diff --git a/libsrc/geos/graph/putchar.s b/libsrc/geos/graph/put_char.s
similarity index 100%
rename from libsrc/geos/graph/putchar.s
rename to libsrc/geos/graph/put_char.s