diff --git a/Common/Data/Format/JSONReader.h b/Common/Data/Format/JSONReader.h
index 792d6a669a..0f5804ecaa 100644
--- a/Common/Data/Format/JSONReader.h
+++ b/Common/Data/Format/JSONReader.h
@@ -1,3 +1,5 @@
+#pragma once
+
 #include <cstring>
 #include <string>
 #include <vector>
diff --git a/Common/Data/Format/JSONWriter.h b/Common/Data/Format/JSONWriter.h
index d82b7151cf..0938c4e809 100644
--- a/Common/Data/Format/JSONWriter.h
+++ b/Common/Data/Format/JSONWriter.h
@@ -9,6 +9,8 @@
 //
 // Zero dependencies apart from stdlib (if you remove the vhjson usage.)
 
+#pragma once
+
 #include <string>
 #include <vector>
 #include <sstream>
diff --git a/Common/Input/GestureDetector.h b/Common/Input/GestureDetector.h
index 39c95dbaec..3e5754a7ab 100644
--- a/Common/Input/GestureDetector.h
+++ b/Common/Input/GestureDetector.h
@@ -1,3 +1,5 @@
+#pragma once
+
 #include <cstdint>
 #include "Common/Input/InputState.h"
 #include "Common/Math/geom2d.h"
diff --git a/Core/HLE/KernelThreadDebugInterface.h b/Core/HLE/KernelThreadDebugInterface.h
index aa48bdb8bb..41260ad7c0 100644
--- a/Core/HLE/KernelThreadDebugInterface.h
+++ b/Core/HLE/KernelThreadDebugInterface.h
@@ -15,6 +15,8 @@
 // Official git repository and contact information can be found at
 // https://github.com/hrydgard/ppsspp and http://www.ppsspp.org/.
 
+#pragma once
+
 #include <cstdio>
 #include "Core/HLE/sceKernelThread.h"
 #include "Core/MIPS/MIPSDebugInterface.h"
diff --git a/Core/HW/AsyncIOManager.h b/Core/HW/AsyncIOManager.h
index 59d50050cf..1145db17ac 100644
--- a/Core/HW/AsyncIOManager.h
+++ b/Core/HW/AsyncIOManager.h
@@ -15,6 +15,8 @@
 // Official git repository and contact information can be found at
 // https://github.com/hrydgard/ppsspp and http://www.ppsspp.org/.
 
+#pragma once
+
 #include <map>
 #include <set>
 #include <mutex>
diff --git a/Core/MIPS/IR/IRNativeCommon.h b/Core/MIPS/IR/IRNativeCommon.h
index 93273f6f0f..7da5d3a831 100644
--- a/Core/MIPS/IR/IRNativeCommon.h
+++ b/Core/MIPS/IR/IRNativeCommon.h
@@ -15,6 +15,8 @@
 // Official git repository and contact information can be found at
 // https://github.com/hrydgard/ppsspp and http://www.ppsspp.org/.
 
+#pragma once
+
 #include <unordered_map>
 #include "Core/MIPS/IR/IRJit.h"
 #include "Core/MIPS/JitCommon/JitBlockCache.h"
diff --git a/Core/SaveState.h b/Core/SaveState.h
index 864dcc8cec..d7bd484c5b 100644
--- a/Core/SaveState.h
+++ b/Core/SaveState.h
@@ -15,6 +15,8 @@
 // Official git repository and contact information can be found at
 // https://github.com/hrydgard/ppsspp and http://www.ppsspp.org/.
 
+#pragma once
+
 #include <functional>
 #include <string>
 #include <vector>
diff --git a/Core/Util/DisArm64.h b/Core/Util/DisArm64.h
index ced77f2cc2..feb98ea9bc 100644
--- a/Core/Util/DisArm64.h
+++ b/Core/Util/DisArm64.h
@@ -18,6 +18,8 @@
 // Basic ARM64 disassembler.
 // No promises of accuracy, mostly just made to debug JIT code.
 
+#pragma once
+
 #include <cstdint>
 
 typedef bool (*SymbolCallback)(char *buffer, int bufsize, uint8_t *address);
diff --git a/Core/WebServer.h b/Core/WebServer.h
index d04b888761..e2713a6e0c 100644
--- a/Core/WebServer.h
+++ b/Core/WebServer.h
@@ -15,6 +15,8 @@
 // Official git repository and contact information can be found at
 // https://github.com/hrydgard/ppsspp and http://www.ppsspp.org/.
 
+#pragma once
+
 enum class WebServerFlags {
 	DISCS = 1,
 	DEBUGGER = 2,
diff --git a/GPU/Debugger/GECommandTable.h b/GPU/Debugger/GECommandTable.h
index 01d2059079..cced7c243e 100644
--- a/GPU/Debugger/GECommandTable.h
+++ b/GPU/Debugger/GECommandTable.h
@@ -15,6 +15,8 @@
 // Official git repository and contact information can be found at
 // https://github.com/hrydgard/ppsspp and http://www.ppsspp.org/.
 
+#pragma once
+
 #include "GPU/ge_constants.h"
 
 enum class GECmdFormat {
diff --git a/GPU/GeDisasm.h b/GPU/GeDisasm.h
index 7a7949e218..aff2d73841 100644
--- a/GPU/GeDisasm.h
+++ b/GPU/GeDisasm.h
@@ -15,6 +15,8 @@
 // Official git repository and contact information can be found at
 // https://github.com/hrydgard/ppsspp and http://www.ppsspp.org/.
 
+#pragma once
+
 #include "Common/CommonTypes.h"
 
 void GeDescribeVertexType(u32 op, char *buffer, int len = 256);
diff --git a/UI/CwCheatScreen.h b/UI/CwCheatScreen.h
index 7a7578c76e..ec6414598d 100644
--- a/UI/CwCheatScreen.h
+++ b/UI/CwCheatScreen.h
@@ -15,6 +15,8 @@
 // Official git repository and contact information can be found at
 // https://github.com/hrydgard/ppsspp and http://www.ppsspp.org/.
 
+#pragma once
+
 #include <cstdint>
 #include <functional>