diff --git a/dsp_lib.h b/dsp_lib.hpp
similarity index 100%
rename from dsp_lib.h
rename to dsp_lib.hpp
diff --git a/fifo.h b/fifo.hpp
similarity index 100%
rename from fifo.h
rename to fifo.hpp
diff --git a/sndlock.cpp b/sndlock.cpp
index 8e09e7b..65ad41b 100644
--- a/sndlock.cpp
+++ b/sndlock.cpp
@@ -14,8 +14,8 @@
 #include "imgui_impl_glfw.h"
 #include "imgui_impl_opengl3.h"
 
-#include "dsp_lib.h"
-#include "fifo.h"
+#include "dsp_lib.hpp"
+#include "fifo.hpp"
 
 #define SND_BITS 24
 #define SND_PCHAN 2