diff --git a/UI/audio-encoders.hpp b/UI/audio-encoders.hpp
index 81c69e6da..7bbde42da 100644
--- a/UI/audio-encoders.hpp
+++ b/UI/audio-encoders.hpp
@@ -1,3 +1,5 @@
+#pragma once
+
 #include <obs.hpp>
 
 #include <map>
diff --git a/UI/expand-checkbox.hpp b/UI/expand-checkbox.hpp
index 375a4ce55..b83160d00 100644
--- a/UI/expand-checkbox.hpp
+++ b/UI/expand-checkbox.hpp
@@ -1,3 +1,5 @@
+#pragma once
+
 #include <QCheckBox>
 
 class ExpandCheckBox : public QCheckBox {
diff --git a/UI/frontend-plugins/decklink-output-ui/decklink-ui-main.h b/UI/frontend-plugins/decklink-output-ui/decklink-ui-main.h
index 85ce556a1..d3683fa9f 100644
--- a/UI/frontend-plugins/decklink-output-ui/decklink-ui-main.h
+++ b/UI/frontend-plugins/decklink-output-ui/decklink-ui-main.h
@@ -1,3 +1,5 @@
+#pragma once
+
 void output_start();
 void output_stop();
 OBSData load_settings();
diff --git a/UI/frontend-plugins/frontend-tools/scripts.hpp b/UI/frontend-plugins/frontend-tools/scripts.hpp
index f638c3fda..e6e5560b3 100644
--- a/UI/frontend-plugins/frontend-tools/scripts.hpp
+++ b/UI/frontend-plugins/frontend-tools/scripts.hpp
@@ -1,3 +1,5 @@
+#pragma once
+
 #include <QWidget>
 #include <QString>
 
diff --git a/UI/hotkey-edit.hpp b/UI/hotkey-edit.hpp
index 3299e2803..e7e7422f2 100644
--- a/UI/hotkey-edit.hpp
+++ b/UI/hotkey-edit.hpp
@@ -15,6 +15,8 @@
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 ******************************************************************************/
 
+#pragma once
+
 #include <QLineEdit>
 #include <QKeyEvent>
 #include <QPushButton>
diff --git a/UI/locked-checkbox.hpp b/UI/locked-checkbox.hpp
index 017470f72..8510f4668 100644
--- a/UI/locked-checkbox.hpp
+++ b/UI/locked-checkbox.hpp
@@ -1,3 +1,5 @@
+#pragma once
+
 #include <QCheckBox>
 #include <QPixmap>
 
diff --git a/UI/source-label.hpp b/UI/source-label.hpp
index 03b9be62a..6bba24e65 100644
--- a/UI/source-label.hpp
+++ b/UI/source-label.hpp
@@ -15,6 +15,8 @@
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 ******************************************************************************/
 
+#pragma once
+
 #include <QLabel>
 #include <obs.hpp>
 
diff --git a/UI/visibility-checkbox.hpp b/UI/visibility-checkbox.hpp
index 47c5d8990..3112c5db1 100644
--- a/UI/visibility-checkbox.hpp
+++ b/UI/visibility-checkbox.hpp
@@ -1,3 +1,5 @@
+#pragma once
+
 #include <QCheckBox>
 #include <QPixmap>
 
diff --git a/libobs/audio-monitoring/win32/wasapi-output.h b/libobs/audio-monitoring/win32/wasapi-output.h
index c3523b51d..8c4286855 100644
--- a/libobs/audio-monitoring/win32/wasapi-output.h
+++ b/libobs/audio-monitoring/win32/wasapi-output.h
@@ -1,3 +1,5 @@
+#pragma once
+
 #include <windows.h>
 #include <mmdeviceapi.h>
 #include <audioclient.h>
diff --git a/plugins/text-freetype2/obs-convenience.h b/plugins/text-freetype2/obs-convenience.h
index 7a717d783..3da3b98bb 100644
--- a/plugins/text-freetype2/obs-convenience.h
+++ b/plugins/text-freetype2/obs-convenience.h
@@ -15,6 +15,8 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 ******************************************************************************/
 
+#pragma once
+
 #include <obs-module.h>
 
 gs_vertbuffer_t *create_uv_vbuffer(uint32_t num_verts, bool add_color);
diff --git a/plugins/text-freetype2/text-freetype2.h b/plugins/text-freetype2/text-freetype2.h
index a3fd49bb7..654b3034f 100644
--- a/plugins/text-freetype2/text-freetype2.h
+++ b/plugins/text-freetype2/text-freetype2.h
@@ -15,6 +15,8 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 ******************************************************************************/
 
+#pragma once
+
 #include <obs-module.h>
 #include <ft2build.h>