diff --git a/pcsx2/CDVD/CDVD_internal.h b/pcsx2/CDVD/CDVD_internal.h
index 8ceebe26a1..bce277d6e2 100644
--- a/pcsx2/CDVD/CDVD_internal.h
+++ b/pcsx2/CDVD/CDVD_internal.h
@@ -13,8 +13,7 @@
  *  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __CDVD_INTERNAL_H__
-#define __CDVD_INTERNAL_H__
+#pragma once
 
 /*
 Interrupts - values are flag bits.
@@ -289,5 +288,3 @@ static u8 biosLangDefaults[8][16] =
 	{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}, // Free  (Japanese, no examples to use)
 	{0x30, 0x2B, 0x80, 0x00, 0x00, 0x70, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x4B}, // China (Simplified Chinese)
 };
-
-#endif
diff --git a/pcsx2/CDVD/CDVDdiscReader.h b/pcsx2/CDVD/CDVDdiscReader.h
index a0236ed687..3a2f596e13 100644
--- a/pcsx2/CDVD/CDVDdiscReader.h
+++ b/pcsx2/CDVD/CDVDdiscReader.h
@@ -13,9 +13,7 @@
  *  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __CDVD_DISC_READER_H__
-#define __CDVD_DISC_READER_H__
-
+#pragma once
 
 #if defined(_WIN32)
 #define NOMINMAX
@@ -101,4 +99,3 @@ s32 cdvdDirectReadSector(u32 sector, s32 mode, u8* buffer);
 s32 cdvdGetMediaType();
 s32 cdvdRefreshData();
 void cdvdParseTOC();
-#endif /* __CDVD_DISC_READER_H__ */
\ No newline at end of file
diff --git a/pcsx2/CDVD/Ps1CD.h b/pcsx2/CDVD/Ps1CD.h
index 0197f5529e..fc0468b04e 100644
--- a/pcsx2/CDVD/Ps1CD.h
+++ b/pcsx2/CDVD/Ps1CD.h
@@ -13,8 +13,7 @@
  *  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __CDROM_H__
-#define __CDROM_H__
+#pragma once
 
 #include "CDVDaccess.h"
 
@@ -99,5 +98,3 @@ void cdrWrite0(u8 rt);
 void cdrWrite1(u8 rt);
 void cdrWrite2(u8 rt);
 void cdrWrite3(u8 rt);
-
-#endif /* __CDROM_H__ */
diff --git a/pcsx2/CDVD/zlib_indexed.h b/pcsx2/CDVD/zlib_indexed.h
index 83f3b4daca..2524f93790 100644
--- a/pcsx2/CDVD/zlib_indexed.h
+++ b/pcsx2/CDVD/zlib_indexed.h
@@ -95,8 +95,7 @@ Comments) 1950 to 1952 in the files http://tools.ietf.org/html/rfc1950
    index in a file.
  */
 
-#ifndef __ZLIB_INDEXED_H__
-#define __ZLIB_INDEXED_H__
+#pragma once
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -504,5 +503,3 @@ extract_ret:
 
 	return ret;
 }
-
-#endif /* __ZLIB_INDEXED_H__ */
diff --git a/pcsx2/COP0.h b/pcsx2/COP0.h
index 93dc3132dd..3ed3c48cbf 100644
--- a/pcsx2/COP0.h
+++ b/pcsx2/COP0.h
@@ -13,8 +13,7 @@
  *  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __COP0_H__
-#define __COP0_H__
+#pragma once
 
 extern void WriteCP0Status(u32 value);
 extern void WriteCP0Config(u32 value);
@@ -25,6 +24,3 @@ extern void MapTLB(int i);
 
 extern void COP0_UpdatePCCR();
 extern void COP0_DiagnosticPCCR();
-
-
-#endif /* __COP0_H__ */
diff --git a/pcsx2/Cache.h b/pcsx2/Cache.h
index 950a64a08d..1f11a22310 100644
--- a/pcsx2/Cache.h
+++ b/pcsx2/Cache.h
@@ -13,8 +13,7 @@
  *  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __CACHE_H__
-#define __CACHE_H__
+#pragma once
 
 #include "Common.h"
 #include "SingleRegisterTypes.h"
@@ -30,5 +29,3 @@ u16 readCache16(u32 mem);
 u32 readCache32(u32 mem);
 RETURNS_R64  readCache64(u32 mem);
 RETURNS_R128 readCache128(u32 mem);
-
-#endif /* __CACHE_H__ */
diff --git a/pcsx2/DEV9/DEV9.h b/pcsx2/DEV9/DEV9.h
index 7319ef2d94..c01307e4fc 100644
--- a/pcsx2/DEV9/DEV9.h
+++ b/pcsx2/DEV9/DEV9.h
@@ -13,8 +13,7 @@
  *  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __DEV9_H__
-#define __DEV9_H__
+#pragma once
 
 #include <stdio.h>
 #include <string>
@@ -722,4 +721,3 @@ void DEV9CheckChanges(const Pcsx2Config& old_config);
 #ifdef _WIN32
 #pragma warning(error : 4013)
 #endif
-#endif
diff --git a/pcsx2/Elfheader.h b/pcsx2/Elfheader.h
index a5216b449c..6b08001582 100644
--- a/pcsx2/Elfheader.h
+++ b/pcsx2/Elfheader.h
@@ -13,8 +13,7 @@
  *  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __ELF_H__
-#define __ELF_H__
+#pragma once
 
 #include "common/SafeArray.h"
 #include "common/SafeArray.inl"
@@ -164,5 +163,3 @@ extern u32 ElfEntry;
 extern std::pair<u32,u32> ElfTextRange;
 extern std::string LastELF;
 extern bool isPSXElf;
-
-#endif
diff --git a/pcsx2/IPU/mpeg2lib/Vlc.h b/pcsx2/IPU/mpeg2lib/Vlc.h
index 5463db8fd3..c2a3c61b1e 100644
--- a/pcsx2/IPU/mpeg2lib/Vlc.h
+++ b/pcsx2/IPU/mpeg2lib/Vlc.h
@@ -27,8 +27,7 @@
 // just result in the linker having to remove a whole lot of redundant/unused decoder
 // tables and static functions. -- air
 
-#ifndef __VLC_H__
-#define __VLC_H__
+#pragma once
 
 static __fi int GETWORD()
 {
@@ -662,5 +661,3 @@ alignas(16) static const DCTtabSet DCT =
 	  {30,1,16}, {29,1,16}, {28,1,16}, {27,1,16} }
 
 };
-
-#endif//__VLC_H__
diff --git a/pcsx2/IopBios.h b/pcsx2/IopBios.h
index 8551c745fb..730f013bfb 100644
--- a/pcsx2/IopBios.h
+++ b/pcsx2/IopBios.h
@@ -13,8 +13,7 @@
  *  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __PSXBIOS_H__
-#define __PSXBIOS_H__
+#pragma once
 
 #define IOP_ENOENT 2
 #define IOP_EIO 5
@@ -87,5 +86,3 @@ namespace R3000A
 } // namespace R3000A
 
 extern void Hle_SetElfPath(const char* elfFileName);
-
-#endif /* __PSXBIOS_H__ */
diff --git a/pcsx2/IopCounters.h b/pcsx2/IopCounters.h
index fc346346d2..20d98f200f 100644
--- a/pcsx2/IopCounters.h
+++ b/pcsx2/IopCounters.h
@@ -13,8 +13,7 @@
  *  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __PSXCOUNTERS_H__
-#define __PSXCOUNTERS_H__
+#pragma once
 
 struct psxCounter {
 	u64 count, target;
@@ -44,5 +43,3 @@ extern void psxVBlankStart();
 extern void psxVBlankEnd();
 extern void psxCheckStartGate16(int i);
 extern void psxCheckEndGate16(int i);
-
-#endif /* __PSXCOUNTERS_H__ */
diff --git a/pcsx2/IopGte.h b/pcsx2/IopGte.h
index aab5ac6c33..1836567a64 100644
--- a/pcsx2/IopGte.h
+++ b/pcsx2/IopGte.h
@@ -14,8 +14,7 @@
 *  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#ifndef __GTE_H__
-#define __GTE_H__
+#pragma once
 
 void gteMFC2();
 void gteCFC2();
@@ -46,5 +45,3 @@ void gteRTPT();
 void gteGPF();
 void gteGPL();
 void gteNCCT();
-
-#endif /* __GTE_H__ */
\ No newline at end of file
diff --git a/pcsx2/IopSio2.h b/pcsx2/IopSio2.h
index aed1a822c6..adbc3ddc56 100644
--- a/pcsx2/IopSio2.h
+++ b/pcsx2/IopSio2.h
@@ -13,9 +13,7 @@
  *  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __PSXSIO2_H__
-#define __PSXSIO2_H__
-
+#pragma once
 
 #define BUFSIZE	8448
 
@@ -91,6 +89,3 @@ void psxDma12(u32 madr, u32 bcr, u32 chcr);
 
 void psxDMA11Interrupt();
 void psxDMA12Interrupt();
-
-#endif /* __PSXSIO2_H__ */
-
diff --git a/pcsx2/Mdec.h b/pcsx2/Mdec.h
index 81556ae64c..a9db94f09a 100644
--- a/pcsx2/Mdec.h
+++ b/pcsx2/Mdec.h
@@ -16,9 +16,7 @@
  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
  */
 
-#ifndef __MDEC_H__
-#define __MDEC_H__
-
+#pragma once
 
 // mdec status:
 #define MDEC_BUSY 0x20000000
@@ -100,5 +98,3 @@ void iqtab_init(int *iqtab,unsigned char *iq_y);
 void round_init(void);
 void yuv2rgb24(int *blk,unsigned char *image);
 void yuv2rgb15(int *blk,u16 *image);
-
-#endif /* __MDEC_H__ */
diff --git a/pcsx2/R3000A.h b/pcsx2/R3000A.h
index 8d07abc3ae..40d664a720 100644
--- a/pcsx2/R3000A.h
+++ b/pcsx2/R3000A.h
@@ -13,8 +13,7 @@
  *  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __R3000A_H__
-#define __R3000A_H__
+#pragma once
 
 #include <stdio.h>
 
@@ -215,5 +214,3 @@ extern void (*psxCP2BSC[32])();
 
 extern void psxBiosReset();
 extern bool psxBiosCall();
-
-#endif /* __R3000A_H__ */
diff --git a/pcsx2/R5900OpcodeTables.h b/pcsx2/R5900OpcodeTables.h
index 8a0b7f21b8..c279d600a3 100644
--- a/pcsx2/R5900OpcodeTables.h
+++ b/pcsx2/R5900OpcodeTables.h
@@ -12,8 +12,7 @@
  *  You should have received a copy of the GNU General Public License along with PCSX2.
  *  If not, see <http://www.gnu.org/licenses/>.
  */
-#ifndef _R5900_OPCODETABLES_H
-#define _R5900_OPCODETABLES_H
+#pragma once
 
 #include "common/Pcsx2Defs.h"
 
@@ -931,5 +930,3 @@ void VRGET();
 void VRINIT();
 void VRXOR();
 //*******************END OF SPECIAL2 *********************
-
-#endif
diff --git a/pcsx2/RDebug/deci2.h b/pcsx2/RDebug/deci2.h
index 7adbfdb776..623172fa68 100644
--- a/pcsx2/RDebug/deci2.h
+++ b/pcsx2/RDebug/deci2.h
@@ -13,8 +13,7 @@
  *  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __DECI2_H__
-#define __DECI2_H__
+#pragma once
 
 #include "Common.h"
 #include "deci2_dcmp.h"
@@ -61,5 +60,3 @@ extern s32		connected;
 
 int	writeData(const u8 *result);
 void	exchangeSD(DECI2_HEADER *h);
-
-#endif//__DECI2_H__
diff --git a/pcsx2/RDebug/deci2_dbgp.h b/pcsx2/RDebug/deci2_dbgp.h
index d8147c6dd0..68a15a435f 100644
--- a/pcsx2/RDebug/deci2_dbgp.h
+++ b/pcsx2/RDebug/deci2_dbgp.h
@@ -13,13 +13,10 @@
  *  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __DECI2DBGP_H__
-#define __DECI2DBGP_H__
+#pragma once
 
 #include "Common.h"
 #include "deci2.h"
 
 void D2_DBGP(const u8 *inbuffer, u8 *outbuffer, char *message, char *eepc, char *ioppc, char *eecy, char *iopcy);
 void sendBREAK(u8 source, u16 id, u8 code, u8 result, u8 count);
-
-#endif//__DECI2DBGP_H__
diff --git a/pcsx2/RDebug/deci2_dcmp.h b/pcsx2/RDebug/deci2_dcmp.h
index dfa0eac8c6..8091949dad 100644
--- a/pcsx2/RDebug/deci2_dcmp.h
+++ b/pcsx2/RDebug/deci2_dcmp.h
@@ -13,13 +13,10 @@
  *  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __DECI2DCMP_H__
-#define __DECI2DCMP_H__
+#pragma once
 
 #include "Common.h"
 #include "deci2.h"
 
 void D2_DCMP(const u8 *inbuffer, u8 *outbuffer, char *message);
 void sendDCMP(u16 protocol, u8 source, u8 destination, u8 type, u8 code, char *data, int size);
-
-#endif//__DECI2DCMP_H__
diff --git a/pcsx2/RDebug/deci2_drfp.h b/pcsx2/RDebug/deci2_drfp.h
index 975bab6417..e6e7b0801e 100644
--- a/pcsx2/RDebug/deci2_drfp.h
+++ b/pcsx2/RDebug/deci2_drfp.h
@@ -13,12 +13,9 @@
  *  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __DECI2DRFP_H__
-#define __DECI2DRFP_H__
+#pragma once
 
 #include "Common.h"
 #include "deci2.h"
 
 void D2_(char *inbuffer, char *outbuffer, char *message);
-
-#endif//__DECI2DRFP_H__
diff --git a/pcsx2/RDebug/deci2_iloadp.h b/pcsx2/RDebug/deci2_iloadp.h
index 7efa22767b..b05a6f2d5c 100644
--- a/pcsx2/RDebug/deci2_iloadp.h
+++ b/pcsx2/RDebug/deci2_iloadp.h
@@ -13,12 +13,9 @@
  *  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __DECI2ILOADP_H__
-#define __DECI2ILOADP_H__
+#pragma once
 
 #include "Common.h"
 #include "deci2.h"
 
 void D2_ILOADP(const u8 *inbuffer, u8 *outbuffer, char *message);
-
-#endif//__DECI2ILOADP_H__
diff --git a/pcsx2/RDebug/deci2_netmp.h b/pcsx2/RDebug/deci2_netmp.h
index 24f9933a7a..83e3f6c2f7 100644
--- a/pcsx2/RDebug/deci2_netmp.h
+++ b/pcsx2/RDebug/deci2_netmp.h
@@ -1,4 +1,4 @@
-    /*  PCSX2 - PS2 Emulator for PCs
+/*  PCSX2 - PS2 Emulator for PCs
  *  Copyright (C) 2002-2010  PCSX2 Dev Team
  *
  *  PCSX2 is free software: you can redistribute it and/or modify it under the terms
@@ -13,12 +13,9 @@
  *  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __DECI2NETMP_H__
-#define __DECI2NETMP_H__
+#pragma once
 
 #include "Common.h"
 #include "deci2.h"
 
 void D2_NETMP(const u8 *inbuffer, u8 *outbuffer, char *message);
-
-#endif//__DECI2NETMP_H__
diff --git a/pcsx2/RDebug/deci2_ttyp.h b/pcsx2/RDebug/deci2_ttyp.h
index 2c3672da2a..4b6b2d06c9 100644
--- a/pcsx2/RDebug/deci2_ttyp.h
+++ b/pcsx2/RDebug/deci2_ttyp.h
@@ -13,13 +13,10 @@
  *  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __DECI2TTYP_H__
-#define __DECI2TTYP_H__
+#pragma once
 
 #include "Common.h"
 #include "deci2.h"
 
 //void D2_(char *inbuffer, char *outbuffer, char *message);
 void sendTTYP(u16 protocol, u8 source, char *data);
-
-#endif//__DECI2TTYP_H__
diff --git a/pcsx2/SPR.h b/pcsx2/SPR.h
index ad61c3f5f2..980044fbc6 100644
--- a/pcsx2/SPR.h
+++ b/pcsx2/SPR.h
@@ -13,12 +13,9 @@
  *  If not, see <http://www.gnu.org/licenses/>.
  */
 
-
-#ifndef __SPR_H__
-#define __SPR_H__
+#pragma once
 
 extern void dmaSPR0();
 extern void dmaSPR1();
 extern void SPRFROMinterrupt();
 extern void SPRTOinterrupt();
-#endif /* __SPR_H__ */
diff --git a/pcsx2/SPU2/Host/Config.h b/pcsx2/SPU2/Host/Config.h
index 062fcd91d8..e63fd5d7ff 100644
--- a/pcsx2/SPU2/Host/Config.h
+++ b/pcsx2/SPU2/Host/Config.h
@@ -13,8 +13,7 @@
  *  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef CONFIG_H_INCLUDED
-#define CONFIG_H_INCLUDED
+#pragma once
 
 #include <string>
 
@@ -101,5 +100,3 @@ namespace SoundtouchCfg
 }; // namespace SoundtouchCfg
 
 void ReadSettings();
-
-#endif // CONFIG_H_INCLUDED
diff --git a/pcsx2/SPU2/Host/Dialogs.h b/pcsx2/SPU2/Host/Dialogs.h
index aeda5f9824..832c6fd6e6 100644
--- a/pcsx2/SPU2/Host/Dialogs.h
+++ b/pcsx2/SPU2/Host/Dialogs.h
@@ -13,8 +13,7 @@
  *  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef DIALOG_H_INCLUDED
-#define DIALOG_H_INCLUDED
+#pragma once
 
 #include "SPU2/Global.h"
 #include "SPU2/Config.h"
@@ -26,5 +25,3 @@ namespace DebugConfig
 
 extern void CfgSetSettingsDir(const char* dir);
 extern void CfgSetLogDir(const char* dir);
-
-#endif
diff --git a/pcsx2/SPU2/interpolate_table.h b/pcsx2/SPU2/interpolate_table.h
index 6064760d7c..488945d531 100644
--- a/pcsx2/SPU2/interpolate_table.h
+++ b/pcsx2/SPU2/interpolate_table.h
@@ -1,5 +1,19 @@
-#ifndef __INTERPOLATE_TABLE_H_
-#define __INTERPOLATE_TABLE_H_
+/*  PCSX2 - PS2 Emulator for PCs
+ *  Copyright (C) 2002-2022  PCSX2 Dev Team
+ *
+ *  PCSX2 is free software: you can redistribute it and/or modify it under the terms
+ *  of the GNU Lesser General Public License as published by the Free Software Found-
+ *  ation, either version 3 of the License, or (at your option) any later version.
+ *
+ *  PCSX2 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 PCSX2.
+ *  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
 
 static const s16 interpTable[0x200] = {
   -0x001, -0x001, -0x001, -0x001, -0x001, -0x001, -0x001, -0x001, //
@@ -67,8 +81,3 @@ static const s16 interpTable[0x200] = {
   0x593A, 0x5949, 0x5958, 0x5965, 0x5971, 0x597C, 0x5986, 0x598F, //
   0x5997, 0x599E, 0x59A4, 0x59A9, 0x59AD, 0x59B0, 0x59B2, 0x59B3  //
 };
-
-
-
-
-#endif // __INTERPOLATE_TABLE_H_
diff --git a/pcsx2/Sif.h b/pcsx2/Sif.h
index 010b5e2915..fd022a439d 100644
--- a/pcsx2/Sif.h
+++ b/pcsx2/Sif.h
@@ -13,8 +13,7 @@
  *  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __SIF_H__
-#define __SIF_H__
+#pragma once
 
 static const int FIFO_SIF_W = 128;
 
@@ -182,5 +181,3 @@ extern bool WriteFifoSingleWord();
 #define sif0tag DMA_TAG(sif0data)
 #define sif1tag DMA_TAG(sif1data)
 #define sif2tag DMA_TAG(sif2data)
-
-#endif /* __SIF_H__ */
diff --git a/pcsx2/Sifcmd.h b/pcsx2/Sifcmd.h
index ebb1f96866..342340b65a 100644
--- a/pcsx2/Sifcmd.h
+++ b/pcsx2/Sifcmd.h
@@ -13,8 +13,7 @@
  *  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __SIFCMD_H__
-#define __SIFCMD_H__
+#pragma once
 
 struct t_sif_dma_transfer
 {
@@ -23,5 +22,3 @@ struct t_sif_dma_transfer
 	s32 size;
 	s32 attr;
 };
-
-#endif//__SIFCMD_H__
diff --git a/pcsx2/x86/iCOP0.h b/pcsx2/x86/iCOP0.h
index 97c10442f5..f12be672b0 100644
--- a/pcsx2/x86/iCOP0.h
+++ b/pcsx2/x86/iCOP0.h
@@ -13,8 +13,7 @@
  *  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __iCOP0_H__
-#define __iCOP0_H__
+#pragma once
 
 #include "COP0.h"
 
@@ -46,4 +45,3 @@ namespace COP0 {
 } // namespace OpcodeImpl
 } // namespace Dynarec
 } // namespace R5900
-#endif
diff --git a/pcsx2/x86/iFPU.h b/pcsx2/x86/iFPU.h
index 4414fb4594..2450793e7e 100644
--- a/pcsx2/x86/iFPU.h
+++ b/pcsx2/x86/iFPU.h
@@ -13,8 +13,7 @@
  *  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __IFPU_H__
-#define __IFPU_H__
+#pragma once
 
 alignas(16) extern const u32 g_minvals[4];
 alignas(16) extern const u32 g_maxvals[4];
@@ -64,5 +63,3 @@ namespace COP1 {
 } // namespace OpcodeImpl
 } // namespace Dynarec
 } // namespace R5900
-
-#endif
diff --git a/pcsx2/x86/iMMI.h b/pcsx2/x86/iMMI.h
index 45c06b751c..4696741dca 100644
--- a/pcsx2/x86/iMMI.h
+++ b/pcsx2/x86/iMMI.h
@@ -18,8 +18,7 @@
 *   MMI opcodes                                          *
 *                                                        *
 *********************************************************/
-#ifndef __IMMI_H__
-#define __IMMI_H__
+#pragma once
 
 namespace R5900 {
 namespace Dynarec {
@@ -142,5 +141,3 @@ namespace MMI {
 } // namespace OpcodeImpl
 } // namespace Dynarec
 } // namespace R5900
-
-#endif
diff --git a/pcsx2/x86/iR5900.h b/pcsx2/x86/iR5900.h
index 1d56e2c836..22fabe2d5e 100644
--- a/pcsx2/x86/iR5900.h
+++ b/pcsx2/x86/iR5900.h
@@ -13,8 +13,7 @@
  *  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __IR5900_H__
-#define __IR5900_H__
+#pragma once
 
 #include "common/emitter/x86emitter.h"
 #include "R5900.h"
@@ -229,5 +228,3 @@ void eeRecompileCodeConstSPECIAL(R5900FNPTR constcode, R5900FNPTR_INFO multicode
 // rd = rs op rt (all regs need to be in xmm)
 int eeRecompileCodeXMM(int xmminfo);
 void eeFPURecompileCode(R5900FNPTR_INFO xmmcode, R5900FNPTR fpucode, int xmminfo);
-
-#endif // __IR5900_H__
diff --git a/pcsx2/x86/iR5900Arit.h b/pcsx2/x86/iR5900Arit.h
index 307bd51c67..bed58810ad 100644
--- a/pcsx2/x86/iR5900Arit.h
+++ b/pcsx2/x86/iR5900Arit.h
@@ -13,8 +13,7 @@
  *  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __IR5900ARIT_H__
-#define __IR5900ARIT_H__
+#pragma once
 
 /*********************************************************
 * Register arithmetic                                    *
@@ -43,4 +42,3 @@ namespace OpcodeImpl {
 } // namespace OpcodeImpl
 } // namespace Dynarec
 } // namespace R5900
-#endif
diff --git a/pcsx2/x86/iR5900AritImm.h b/pcsx2/x86/iR5900AritImm.h
index 18fe48c40a..9cc542cb43 100644
--- a/pcsx2/x86/iR5900AritImm.h
+++ b/pcsx2/x86/iR5900AritImm.h
@@ -13,8 +13,7 @@
  *  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __IR5900ARITIMM_H__
-#define __IR5900ARITIMM_H__
+#pragma once
 
 /*********************************************************
 * Arithmetic with immediate operand                      *
@@ -38,5 +37,3 @@ namespace OpcodeImpl {
 } // namespace OpcodeImpl
 } // namespace Dynarec
 } // namespace R5900
-
-#endif
diff --git a/pcsx2/x86/iR5900Branch.h b/pcsx2/x86/iR5900Branch.h
index 619599b90b..aa6ab6c384 100644
--- a/pcsx2/x86/iR5900Branch.h
+++ b/pcsx2/x86/iR5900Branch.h
@@ -13,8 +13,7 @@
  *  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __IR5900BRANCH_H__
-#define __IR5900BRANCH_H__
+#pragma once
 
 /*********************************************************
 * Shift arithmetic with constant shift                   *
@@ -45,5 +44,3 @@ namespace OpcodeImpl {
 } // namespace OpcodeImpl
 } // namespace Dynarec
 } // namespace R5900
-
-#endif
diff --git a/pcsx2/x86/iR5900Jump.h b/pcsx2/x86/iR5900Jump.h
index ff0e40278d..149e6d0c7f 100644
--- a/pcsx2/x86/iR5900Jump.h
+++ b/pcsx2/x86/iR5900Jump.h
@@ -13,8 +13,7 @@
  *  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __IR5900JUMP_H__
-#define __IR5900JUMP_H__
+#pragma once
 
 /*********************************************************
 * Jump to target                                         *
@@ -33,5 +32,3 @@ namespace OpcodeImpl {
 } // namespace OpcodeImpl
 } // namespace Dynarec
 } // namespace R5900
-
-#endif
diff --git a/pcsx2/x86/iR5900LoadStore.h b/pcsx2/x86/iR5900LoadStore.h
index 817d1f8920..93097c6879 100644
--- a/pcsx2/x86/iR5900LoadStore.h
+++ b/pcsx2/x86/iR5900LoadStore.h
@@ -13,8 +13,8 @@
  *  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __IR5900LOADSTORE_H__
-#define __IR5900LOADSTORE_H__
+#pragma once
+
 /*********************************************************
 * Load and store for GPR                                 *
 * Format:  OP rt, offset(base)                           *
@@ -53,5 +53,3 @@ namespace OpcodeImpl {
 } // namespace OpcodeImpl
 } // namespace Dynarec
 } // namespace R5900
-
-#endif
diff --git a/pcsx2/x86/iR5900Move.h b/pcsx2/x86/iR5900Move.h
index cf05434020..450c1f5015 100644
--- a/pcsx2/x86/iR5900Move.h
+++ b/pcsx2/x86/iR5900Move.h
@@ -13,8 +13,7 @@
  *  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __IR5900MOVE_H__
-#define __IR5900MOVE_H__
+#pragma once
 
 namespace R5900 {
 namespace Dynarec {
@@ -31,5 +30,3 @@ namespace OpcodeImpl {
 } // namespace OpcodeImpl
 } // namespace Dynarec
 } // namespace R5900
-
-#endif
diff --git a/pcsx2/x86/iR5900MultDiv.h b/pcsx2/x86/iR5900MultDiv.h
index 9c75a6f333..94fcaf81ed 100644
--- a/pcsx2/x86/iR5900MultDiv.h
+++ b/pcsx2/x86/iR5900MultDiv.h
@@ -13,8 +13,7 @@
  *  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __IR5900MULTDIV_H__
-#define __IR5900MULTDIV_H__
+#pragma once
 
 /*********************************************************
 * Register mult/div & Register trap logic                *
@@ -33,5 +32,3 @@ namespace OpcodeImpl {
 } // namespace OpcodeImpl
 } // namespace Dynarec
 } // namespace R5900
-
-#endif
diff --git a/pcsx2/x86/iR5900Shift.h b/pcsx2/x86/iR5900Shift.h
index 5b7a9ab9ea..e1530ba6d7 100644
--- a/pcsx2/x86/iR5900Shift.h
+++ b/pcsx2/x86/iR5900Shift.h
@@ -13,8 +13,7 @@
  *  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __IR5900SHIFT_H__
-#define __IR5900SHIFT_H__
+#pragma once
 
 /*********************************************************
 * Shift arithmetic with constant shift                   *
@@ -45,5 +44,3 @@ namespace OpcodeImpl {
 } // namespace OpcodeImpl
 } // namespace Dynarec
 } // namespace R5900
-
-#endif