diff --git a/app/CMakeLists.txt b/app/CMakeLists.txt
index 16ce43556..3fa2e554c 100644
--- a/app/CMakeLists.txt
+++ b/app/CMakeLists.txt
@@ -16,16 +16,12 @@
 
 set(OLIVE_SOURCES
   ${OLIVE_SOURCES}
-  clamp.h
   core.h
   core.cpp
-  lerp.h
   main.cpp
-  rational.h
-  rational.cpp
-  qobjectlistcast.h
 )
 
+add_subdirectory(common)
 add_subdirectory(decoder)
 add_subdirectory(node)
 add_subdirectory(panel)
diff --git a/app/common/CMakeLists.txt b/app/common/CMakeLists.txt
new file mode 100644
index 000000000..6c5ca6ef6
--- /dev/null
+++ b/app/common/CMakeLists.txt
@@ -0,0 +1,25 @@
+# Olive - Non-Linear Video Editor
+# Copyright (C) 2019 Olive Team
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+set(OLIVE_SOURCES
+  ${OLIVE_SOURCES}
+  common/clamp.h
+  common/lerp.h
+  common/rational.h
+  common/rational.cpp
+  common/qobjectlistcast.h
+  PARENT_SCOPE
+)
diff --git a/app/clamp.h b/app/common/clamp.h
similarity index 100%
rename from app/clamp.h
rename to app/common/clamp.h
diff --git a/app/lerp.h b/app/common/lerp.h
similarity index 100%
rename from app/lerp.h
rename to app/common/lerp.h
diff --git a/app/qobjectlistcast.h b/app/common/qobjectlistcast.h
similarity index 100%
rename from app/qobjectlistcast.h
rename to app/common/qobjectlistcast.h
diff --git a/app/rational.cpp b/app/common/rational.cpp
similarity index 100%
rename from app/rational.cpp
rename to app/common/rational.cpp
diff --git a/app/rational.h b/app/common/rational.h
similarity index 100%
rename from app/rational.h
rename to app/common/rational.h
diff --git a/app/decoder/decoder.h b/app/decoder/decoder.h
index 6b4dd381b..6180f0539 100644
--- a/app/decoder/decoder.h
+++ b/app/decoder/decoder.h
@@ -24,7 +24,7 @@
 #include <QObject>
 #include <stdint.h>
 
-#include "rational.h"
+#include "common/rational.h"
 #include "project/item/footage/footage.h"
 #include "decoder/frame.h"
 
diff --git a/app/decoder/frame.h b/app/decoder/frame.h
index e07cd0621..1fde58258 100644
--- a/app/decoder/frame.h
+++ b/app/decoder/frame.h
@@ -27,7 +27,7 @@ extern "C" {
 
 #include <memory>
 
-#include "rational.h"
+#include "common/rational.h"
 
 /**
  * @brief Abstraction from AVFrame. Currently a simple AVFrame wrapper.
diff --git a/app/node/graph.cpp b/app/node/graph.cpp
index 3ea32b0b9..7f1bb660c 100644
--- a/app/node/graph.cpp
+++ b/app/node/graph.cpp
@@ -20,7 +20,7 @@
 
 #include "graph.h"
 
-#include "qobjectlistcast.h"
+#include "common/qobjectlistcast.h"
 
 NodeGraph::NodeGraph()
 {
diff --git a/app/node/keyframe.h b/app/node/keyframe.h
index 127fd7fa5..e482bccfd 100644
--- a/app/node/keyframe.h
+++ b/app/node/keyframe.h
@@ -23,7 +23,7 @@
 
 #include <QVariant>
 
-#include "rational.h"
+#include "common/rational.h"
 
 class NodeKeyframe
 {
diff --git a/app/node/node.cpp b/app/node/node.cpp
index e079616df..6431edc9a 100644
--- a/app/node/node.cpp
+++ b/app/node/node.cpp
@@ -20,7 +20,7 @@
 
 #include "node.h"
 
-#include "qobjectlistcast.h"
+#include "common/qobjectlistcast.h"
 
 Node::Node(QObject *parent) :
   QObject(parent)
diff --git a/app/node/node.h b/app/node/node.h
index ade4bfe22..f159549b9 100644
--- a/app/node/node.h
+++ b/app/node/node.h
@@ -23,9 +23,9 @@
 
 #include <QObject>
 
+#include "common/rational.h"
 #include "node/input.h"
 #include "node/output.h"
-#include "rational.h"
 
 class Node : public QObject
 {
diff --git a/app/node/param.h b/app/node/param.h
index b83c916d5..4f4fb8ac0 100644
--- a/app/node/param.h
+++ b/app/node/param.h
@@ -24,8 +24,8 @@
 #include <QObject>
 #include <QVariant>
 
+#include "common/rational.h"
 #include "node/edge.h"
-#include "rational.h"
 
 class Node;
 
diff --git a/app/project/item/footage/audiostream.h b/app/project/item/footage/audiostream.h
index fec4dd438..92e826301 100644
--- a/app/project/item/footage/audiostream.h
+++ b/app/project/item/footage/audiostream.h
@@ -25,7 +25,7 @@ extern "C" {
 #include <libavcodec/avcodec.h>
 }
 
-#include "rational.h"
+#include "common/rational.h"
 #include "stream.h"
 
 /**
diff --git a/app/project/item/footage/footage.h b/app/project/item/footage/footage.h
index d9790ab0c..264ed5621 100644
--- a/app/project/item/footage/footage.h
+++ b/app/project/item/footage/footage.h
@@ -24,10 +24,10 @@
 #include <QList>
 #include <QDateTime>
 
+#include "common/rational.h"
 #include "project/item/item.h"
 #include "project/item/footage/audiostream.h"
 #include "project/item/footage/videostream.h"
-#include "rational.h"
 
 /**
  * @brief A reference to an external media file with metadata in a project structure
diff --git a/app/project/item/footage/stream.h b/app/project/item/footage/stream.h
index f668f71e1..099703a45 100644
--- a/app/project/item/footage/stream.h
+++ b/app/project/item/footage/stream.h
@@ -21,7 +21,7 @@
 #ifndef STREAM_H
 #define STREAM_H
 
-#include "rational.h"
+#include "common/rational.h"
 
 class Footage;
 
diff --git a/app/project/item/footage/videostream.h b/app/project/item/footage/videostream.h
index a45102bdf..21eabcd3f 100644
--- a/app/project/item/footage/videostream.h
+++ b/app/project/item/footage/videostream.h
@@ -21,7 +21,7 @@
 #ifndef VIDEOSTREAM_H
 #define VIDEOSTREAM_H
 
-#include "rational.h"
+#include "common/rational.h"
 #include "stream.h"
 
 /**
diff --git a/app/project/item/sequence/sequence.h b/app/project/item/sequence/sequence.h
index 9738a8964..249c69318 100644
--- a/app/project/item/sequence/sequence.h
+++ b/app/project/item/sequence/sequence.h
@@ -21,9 +21,9 @@
 #ifndef SEQUENCE_H
 #define SEQUENCE_H
 
+#include "common/rational.h"
 #include "node/graph.h"
 #include "project/item/item.h"
-#include "rational.h"
 
 class Sequence : public Item, public NodeGraph
 {
diff --git a/app/widget/nodeview/nodeviewedge.cpp b/app/widget/nodeview/nodeviewedge.cpp
index ac4994571..793b77513 100644
--- a/app/widget/nodeview/nodeviewedge.cpp
+++ b/app/widget/nodeview/nodeviewedge.cpp
@@ -22,8 +22,8 @@
 
 #include <QDebug>
 
-#include "clamp.h"
-#include "lerp.h"
+#include "common/clamp.h"
+#include "common/lerp.h"
 #include "nodeview.h"
 #include "nodeviewitem.h"
 
diff --git a/app/widget/viewer/viewer.h b/app/widget/viewer/viewer.h
index f45425408..170547937 100644
--- a/app/widget/viewer/viewer.h
+++ b/app/widget/viewer/viewer.h
@@ -25,7 +25,7 @@
 #include <QPushButton>
 #include <QLabel>
 
-#include "rational.h"
+#include "common/rational.h"
 #include "viewerglwidget.h"
 #include "widget/playbackcontrols/playbackcontrols.h"