diff --git a/SConstruct b/SConstruct
index 8435bfe51..d425c48b1 100644
--- a/SConstruct
+++ b/SConstruct
@@ -827,7 +827,7 @@ class DXXProgram(DXXCommon):
 'editor/group.cpp',
 'editor/info.cpp',
 'editor/kbuild.cpp',
-'editor/kcurve.c',
+'editor/kcurve.cpp',
 'editor/kfuncs.c',
 'editor/kgame.c',
 'editor/khelp.c',
diff --git a/similar/editor/kcurve.c b/similar/editor/kcurve.cpp
similarity index 100%
rename from similar/editor/kcurve.c
rename to similar/editor/kcurve.cpp