diff --git a/src/process-monitor.c b/src/process-monitor.c
index 3e1bd01..32bf747 100644
--- a/src/process-monitor.c
+++ b/src/process-monitor.c
@@ -14,6 +14,7 @@
 #include <gtk/gtk.h>
 #include <cairo.h>
 
+#include "task-manager.h"
 #include "process-monitor.h"
 
 
diff --git a/src/process-tree-model.c b/src/process-tree-model.c
index 551a722..fdc8c2a 100644
--- a/src/process-tree-model.c
+++ b/src/process-tree-model.c
@@ -16,6 +16,7 @@
 #include <gtk/gtk.h>
 #include <gdk/gdkkeysyms.h>
 
+#include "task-manager.h"
 #include "process-tree-view.h"
 #include "process-tree-model.h"
 
diff --git a/src/process-window.c b/src/process-window.c
index 32cf8e7..57fd6cc 100644
--- a/src/process-window.c
+++ b/src/process-window.c
@@ -29,6 +29,7 @@
 #include <gdk/gdkkeysyms.h>
 
 #include "settings.h"
+#include "task-manager.h"
 #include "process-window.h"
 #if GTK_CHECK_VERSION(3, 0, 0)
 #include "process-window-gtk3_ui.h"