diff --git a/lib/geometry/dgmapper.cc b/lib/geometry/sdgmapper.cc
similarity index 100%
rename from lib/geometry/dgmapper.cc
rename to lib/geometry/sdgmapper.cc
diff --git a/mkninja.sh b/mkninja.sh
index 6931a903..6ee2eaed 100644
--- a/mkninja.sh
+++ b/mkninja.sh
@@ -338,7 +338,7 @@ buildlibrary libbackend.a \
     lib/fluxsource/scpfluxsource.cc \
     lib/fluxsource/sqlitefluxsource.cc \
     lib/fluxsource/testpatternfluxsource.cc \
-    lib/geometry/dgmapper.cc \
+    lib/geometry/sdgmapper.cc \
     lib/globals.cc \
     lib/hexdump.cc \
     lib/imagereader/diskcopyimagereader.cc \