diff --git a/src/ADSR.cpp b/src/ADSR.cpp
index 4b69b58..ca21a04 100644
--- a/src/ADSR.cpp
+++ b/src/ADSR.cpp
@@ -1,4 +1,5 @@
 #include "Fundamental.hpp"
+#include "dsp/digital.hpp"
 
 
 struct ADSR : Module {
diff --git a/src/Delay.cpp b/src/Delay.cpp
index 2eb48e2..f2d58af 100644
--- a/src/Delay.cpp
+++ b/src/Delay.cpp
@@ -1,4 +1,7 @@
 #include "Fundamental.hpp"
+#include "dsp/samplerate.hpp"
+#include "dsp/ringbuffer.hpp"
+#include "dsp/filter.hpp"
 
 
 #define HISTORY_SIZE (1<<21)
diff --git a/src/SEQ3.cpp b/src/SEQ3.cpp
index 383a6d0..c40f401 100644
--- a/src/SEQ3.cpp
+++ b/src/SEQ3.cpp
@@ -1,4 +1,5 @@
 #include "Fundamental.hpp"
+#include "dsp/digital.hpp"
 
 
 struct SEQ3 : Module {
diff --git a/src/Scope.cpp b/src/Scope.cpp
index ad7bd5a..12492df 100644
--- a/src/Scope.cpp
+++ b/src/Scope.cpp
@@ -1,5 +1,6 @@
 #include <string.h>
 #include "Fundamental.hpp"
+#include "dsp/digital.hpp"
 
 
 #define BUFFER_SIZE 512
diff --git a/src/VCO.cpp b/src/VCO.cpp
index 4951f3a..55c5059 100644
--- a/src/VCO.cpp
+++ b/src/VCO.cpp
@@ -1,4 +1,6 @@
 #include "Fundamental.hpp"
+#include "dsp/decimator.hpp"
+#include "dsp/filter.hpp"
 
 
 #define OVERSAMPLE 16