diff --git a/rtengine/CMakeLists.txt b/rtengine/CMakeLists.txt
index 424b3352e..0b003909f 100644
--- a/rtengine/CMakeLists.txt
+++ b/rtengine/CMakeLists.txt
@@ -72,6 +72,7 @@ set(RTENGINESOURCEFILES
     imageio.cc
     improccoordinator.cc
     improcfun.cc
+    impulse_denoise.cc
     init.cc
     iplab2rgb.cc
     ipresize.cc
diff --git a/rtengine/improcfun.cc b/rtengine/improcfun.cc
index 8236aaf37..c22d7b509 100644
--- a/rtengine/improcfun.cc
+++ b/rtengine/improcfun.cc
@@ -28,7 +28,6 @@
 #include "curves.h"
 #include "mytime.h"
 #include "iccstore.h"
-#include "impulse_denoise.h"
 #include "imagesource.h"
 #include "rtthumbnail.h"
 #include "utils.h"
diff --git a/rtengine/impulse_denoise.h b/rtengine/impulse_denoise.cc
similarity index 100%
rename from rtengine/impulse_denoise.h
rename to rtengine/impulse_denoise.cc