diff --git a/Code/Tools/ProjectManager/Source/CreateProjectCtrl.cpp b/Code/Tools/ProjectManager/Source/CreateProjectCtrl.cpp
index 6b19e839d7..205395c935 100644
--- a/Code/Tools/ProjectManager/Source/CreateProjectCtrl.cpp
+++ b/Code/Tools/ProjectManager/Source/CreateProjectCtrl.cpp
@@ -15,6 +15,7 @@
 #include <GemCatalog/GemCatalogScreen.h>
 #include <GemRepo/GemRepoScreen.h>
 #include <ProjectUtils.h>
+#include <DownloadController.h>
 
 #include <QDialogButtonBox>
 #include <QHBoxLayout>
diff --git a/Code/Tools/ProjectManager/Source/GemCatalog/GemCatalogScreen.cpp b/Code/Tools/ProjectManager/Source/GemCatalog/GemCatalogScreen.cpp
index d610154c24..2240ae68d2 100644
--- a/Code/Tools/ProjectManager/Source/GemCatalog/GemCatalogScreen.cpp
+++ b/Code/Tools/ProjectManager/Source/GemCatalog/GemCatalogScreen.cpp
@@ -8,6 +8,11 @@
 
 #include <GemCatalog/GemCatalogScreen.h>
 #include <PythonBindingsInterface.h>
+#include <GemCatalog/GemCatalogHeaderWidget.h>
+#include <GemCatalog/GemFilterWidget.h>
+#include <GemCatalog/GemListView.h>
+#include <GemCatalog/GemInspector.h>
+#include <GemCatalog/GemModel.h>
 #include <GemCatalog/GemListHeaderWidget.h>
 #include <GemCatalog/GemSortFilterProxyModel.h>
 #include <GemCatalog/GemRequirementDialog.h>
@@ -28,6 +33,7 @@
 #include <QFileDialog>
 #include <QMessageBox>
 #include <QHash>
+#include <QStackedWidget>
 
 namespace O3DE::ProjectManager
 {
diff --git a/Code/Tools/ProjectManager/Source/GemCatalog/GemCatalogScreen.h b/Code/Tools/ProjectManager/Source/GemCatalog/GemCatalogScreen.h
index 92cf0bd5f2..dcdf6373ac 100644
--- a/Code/Tools/ProjectManager/Source/GemCatalog/GemCatalogScreen.h
+++ b/Code/Tools/ProjectManager/Source/GemCatalog/GemCatalogScreen.h
@@ -12,20 +12,23 @@
 #include <ScreenWidget.h>
 #include <AzCore/std/smart_ptr/unique_ptr.h>
 #include <AzToolsFramework/UI/Notifications/ToastNotificationsView.h>
-#include <GemCatalog/GemCatalogHeaderWidget.h>
-#include <GemCatalog/GemFilterWidget.h>
-#include <GemCatalog/GemListView.h>
-#include <GemCatalog/GemInspector.h>
-#include <GemCatalog/GemModel.h>
-#include <GemCatalog/GemSortFilterProxyModel.h>
 
 #include <QSet>
 #include <QString>
-#include <QStackedWidget>
 #endif
 
+QT_FORWARD_DECLARE_CLASS(QStackedWidget)
+
 namespace O3DE::ProjectManager
 {
+    QT_FORWARD_DECLARE_CLASS(GemCatalogHeaderWidget)
+    QT_FORWARD_DECLARE_CLASS(GemFilterWidget)
+    QT_FORWARD_DECLARE_CLASS(GemListView)
+    QT_FORWARD_DECLARE_CLASS(GemInspector)
+    QT_FORWARD_DECLARE_CLASS(GemModel)
+    QT_FORWARD_DECLARE_CLASS(GemSortFilterProxyModel)
+    QT_FORWARD_DECLARE_CLASS(DownloadController)
+
     class GemCatalogScreen
         : public ScreenWidget
     {