diff --git a/PrmPkg/Application/PrmInfo/PrmInfo.h b/PrmPkg/Application/PrmInfo/PrmInfo.h
index 3813998e96..5f8cf9dc0e 100644
--- a/PrmPkg/Application/PrmInfo/PrmInfo.h
+++ b/PrmPkg/Application/PrmInfo/PrmInfo.h
@@ -6,8 +6,7 @@
 
 **/
 
-#ifndef PRM_INFO_H_
-#define PRM_INFO_H_
+#pragma once
 
 #include <Base.h>
 #include <Prm.h>
@@ -45,5 +44,3 @@ typedef struct {
 #define ONE_MICROSECOND  (1000)
 #define ONE_MILLISECOND  (1000 * ONE_MICROSECOND)
 #define ONE_SECOND       (1000 * ONE_MILLISECOND)
-
-#endif
diff --git a/PrmPkg/Include/Library/PrmContextBufferLib.h b/PrmPkg/Include/Library/PrmContextBufferLib.h
index 8416b6a6c2..59e2788491 100644
--- a/PrmPkg/Include/Library/PrmContextBufferLib.h
+++ b/PrmPkg/Include/Library/PrmContextBufferLib.h
@@ -7,8 +7,7 @@
 
 **/
 
-#ifndef PRM_CONTEXT_BUFFER_LIB_H_
-#define PRM_CONTEXT_BUFFER_LIB_H_
+#pragma once
 
 #include <Base.h>
 #include <PrmContextBuffer.h>
@@ -95,5 +94,3 @@ GetContextBuffer (
   IN  CONST PRM_MODULE_CONTEXT_BUFFERS  *PrmModuleContextBuffers  OPTIONAL,
   OUT CONST PRM_CONTEXT_BUFFER          **PrmContextBuffer
   );
-
-#endif
diff --git a/PrmPkg/Include/Library/PrmModuleDiscoveryLib.h b/PrmPkg/Include/Library/PrmModuleDiscoveryLib.h
index 341b9b26a0..1a9a273aae 100644
--- a/PrmPkg/Include/Library/PrmModuleDiscoveryLib.h
+++ b/PrmPkg/Include/Library/PrmModuleDiscoveryLib.h
@@ -7,8 +7,7 @@
 
 **/
 
-#ifndef PRM_MODULE_DISCOVERY_LIB_H_
-#define PRM_MODULE_DISCOVERY_LIB_H_
+#pragma once
 
 #include <Base.h>
 #include <PrmContextBuffer.h>
@@ -56,5 +55,3 @@ DiscoverPrmModules (
   OUT UINTN  *ModuleCount    OPTIONAL,
   OUT UINTN  *HandlerCount   OPTIONAL
   );
-
-#endif
diff --git a/PrmPkg/Include/Library/PrmPeCoffLib.h b/PrmPkg/Include/Library/PrmPeCoffLib.h
index a3cbeba007..57d857d812 100644
--- a/PrmPkg/Include/Library/PrmPeCoffLib.h
+++ b/PrmPkg/Include/Library/PrmPeCoffLib.h
@@ -8,8 +8,7 @@
 
 **/
 
-#ifndef PRM_PECOFF_LIB_H_
-#define PRM_PECOFF_LIB_H_
+#pragma once
 
 #include <Base.h>
 #include <PrmExportDescriptor.h>
@@ -107,5 +106,3 @@ GetExportEntryAddress (
   IN  EFI_IMAGE_EXPORT_DIRECTORY  *ImageExportDirectory,
   OUT EFI_PHYSICAL_ADDRESS        *ExportPhysicalAddress
   );
-
-#endif
diff --git a/PrmPkg/Include/Prm.h b/PrmPkg/Include/Prm.h
index 563c7430ab..12fad99527 100644
--- a/PrmPkg/Include/Prm.h
+++ b/PrmPkg/Include/Prm.h
@@ -8,8 +8,7 @@
 
 **/
 
-#ifndef PRM_H_
-#define PRM_H_
+#pragma once
 
 #include <Uefi.h>
 #include <PrmContextBuffer.h>
@@ -48,5 +47,3 @@ EFI_STATUS
   IN VOID                 *ParameterBuffer  OPTIONAL,
   IN PRM_CONTEXT_BUFFER   *ContextBuffer  OPTIONAL
   );
-
-#endif
diff --git a/PrmPkg/Include/PrmContextBuffer.h b/PrmPkg/Include/PrmContextBuffer.h
index 781910d67e..b8fd1239f5 100644
--- a/PrmPkg/Include/PrmContextBuffer.h
+++ b/PrmPkg/Include/PrmContextBuffer.h
@@ -7,8 +7,7 @@
 
 **/
 
-#ifndef PRM_CONTEXT_BUFFER_H_
-#define PRM_CONTEXT_BUFFER_H_
+#pragma once
 
 #include <PrmDataBuffer.h>
 #include <PrmMmio.h>
@@ -167,5 +166,3 @@ typedef struct {
 } PRM_MODULE_CONTEXT_BUFFERS;
 
 #pragma pack(pop)
-
-#endif
diff --git a/PrmPkg/Include/PrmDataBuffer.h b/PrmPkg/Include/PrmDataBuffer.h
index 4613f57cae..6e70dbdd69 100644
--- a/PrmPkg/Include/PrmDataBuffer.h
+++ b/PrmPkg/Include/PrmDataBuffer.h
@@ -7,8 +7,7 @@
 
 **/
 
-#ifndef PRM_DATA_BUFFER_H_
-#define PRM_DATA_BUFFER_H_
+#pragma once
 
 #include <Uefi.h>
 
@@ -47,5 +46,3 @@ typedef struct {
 } PRM_DATA_BUFFER;
 
 #pragma pack(pop)
-
-#endif
diff --git a/PrmPkg/Include/PrmExportDescriptor.h b/PrmPkg/Include/PrmExportDescriptor.h
index 8131b5ade9..6cf979bcfe 100644
--- a/PrmPkg/Include/PrmExportDescriptor.h
+++ b/PrmPkg/Include/PrmExportDescriptor.h
@@ -7,8 +7,7 @@
 
 **/
 
-#ifndef PRM_EXPORT_DESCRIPTOR_H_
-#define PRM_EXPORT_DESCRIPTOR_H_
+#pragma once
 
 #include <Prm.h>
 
@@ -106,4 +105,3 @@ typedef struct {
     { __VA_ARGS__ }                                                                                       \
   }                                                                                                       \
 
-#endif
diff --git a/PrmPkg/Include/PrmMmio.h b/PrmPkg/Include/PrmMmio.h
index 6aca19f912..2122a8caa8 100644
--- a/PrmPkg/Include/PrmMmio.h
+++ b/PrmPkg/Include/PrmMmio.h
@@ -7,8 +7,7 @@
 
 **/
 
-#ifndef PRM_MMIO_H_
-#define PRM_MMIO_H_
+#pragma once
 
 #include <Uefi.h>
 
@@ -41,5 +40,3 @@ typedef struct {
 } PRM_RUNTIME_MMIO_RANGES;
 
 #pragma pack(pop)
-
-#endif
diff --git a/PrmPkg/Include/PrmModule.h b/PrmPkg/Include/PrmModule.h
index 094f7d1226..290ebfb384 100644
--- a/PrmPkg/Include/PrmModule.h
+++ b/PrmPkg/Include/PrmModule.h
@@ -7,8 +7,7 @@
 
 **/
 
-#ifndef PRM_MODULE_H_
-#define PRM_MODULE_H_
+#pragma once
 
 #include <Prm.h>
 #include <PrmContextBuffer.h>
@@ -44,4 +43,3 @@
     IN PRM_CONTEXT_BUFFER   *ContextBuffer      \
     )                                           \
 
-#endif
diff --git a/PrmPkg/Include/PrmModuleImageContext.h b/PrmPkg/Include/PrmModuleImageContext.h
index 0e381442e1..fd2bff9b90 100644
--- a/PrmPkg/Include/PrmModuleImageContext.h
+++ b/PrmPkg/Include/PrmModuleImageContext.h
@@ -7,8 +7,7 @@
 
 **/
 
-#ifndef PRM_MODULE_IMAGE_CONTEXT_H_
-#define PRM_MODULE_IMAGE_CONTEXT_H_
+#pragma once
 
 #include <IndustryStandard/PeImage.h>
 #include <Library/PeCoffLib.h>
@@ -24,5 +23,3 @@ typedef struct {
 } PRM_MODULE_IMAGE_CONTEXT;
 
 #pragma pack(pop)
-
-#endif
diff --git a/PrmPkg/Include/Protocol/PrmConfig.h b/PrmPkg/Include/Protocol/PrmConfig.h
index 4cce6b3c2c..729cd1d578 100644
--- a/PrmPkg/Include/Protocol/PrmConfig.h
+++ b/PrmPkg/Include/Protocol/PrmConfig.h
@@ -11,8 +11,7 @@
 
 **/
 
-#ifndef PRM_CONFIG_H_
-#define PRM_CONFIG_H_
+#pragma once
 
 #include <PrmContextBuffer.h>
 #include <Uefi.h>
@@ -27,5 +26,3 @@ struct _PRM_CONFIG_PROTOCOL {
 };
 
 extern EFI_GUID  gPrmConfigProtocolGuid;
-
-#endif
diff --git a/PrmPkg/Library/DxePrmModuleDiscoveryLib/PrmModuleDiscovery.h b/PrmPkg/Library/DxePrmModuleDiscoveryLib/PrmModuleDiscovery.h
index f6b8962605..227879fe00 100644
--- a/PrmPkg/Library/DxePrmModuleDiscoveryLib/PrmModuleDiscovery.h
+++ b/PrmPkg/Library/DxePrmModuleDiscoveryLib/PrmModuleDiscovery.h
@@ -7,8 +7,7 @@
 
 **/
 
-#ifndef PRM_MODULE_DISCOVERY_H_
-#define PRM_MODULE_DISCOVERY_H_
+#pragma once
 
 #include <PrmModuleImageContext.h>
 
@@ -35,5 +34,3 @@ PRM_MODULE_IMAGE_CONTEXT_LIST_ENTRY *
 CreateNewPrmModuleImageContextListEntry (
   VOID
   );
-
-#endif
diff --git a/PrmPkg/PrmLoaderDxe/PrmAcpiTable.h b/PrmPkg/PrmLoaderDxe/PrmAcpiTable.h
index e2034d4738..e4d336eb66 100644
--- a/PrmPkg/PrmLoaderDxe/PrmAcpiTable.h
+++ b/PrmPkg/PrmLoaderDxe/PrmAcpiTable.h
@@ -8,8 +8,7 @@
 
 **/
 
-#ifndef PRMT_ACPI_TABLE_H_
-#define PRMT_ACPI_TABLE_H_
+#pragma once
 
 #include <Base.h>
 #include <IndustryStandard/Acpi10.h>
@@ -92,5 +91,3 @@ typedef struct {
       PhysicalAddress,                                                     /* UINT64                  PhysicalAddress         */   \
     } \
   }
-
-#endif // _PRMT_ACPI_TABLE_H_
diff --git a/PrmPkg/Samples/PrmSampleContextBufferModule/Include/StaticData.h b/PrmPkg/Samples/PrmSampleContextBufferModule/Include/StaticData.h
index c3a5067c55..4fade3c364 100644
--- a/PrmPkg/Samples/PrmSampleContextBufferModule/Include/StaticData.h
+++ b/PrmPkg/Samples/PrmSampleContextBufferModule/Include/StaticData.h
@@ -8,8 +8,7 @@
 
 **/
 
-#ifndef PRM_STATIC_DATA_SAMPLE_CONTEXT_BUFFER_MODULE_H_
-#define PRM_STATIC_DATA_SAMPLE_CONTEXT_BUFFER_MODULE_H_
+#pragma once
 
 #include <Base.h>
 
@@ -20,5 +19,3 @@ typedef struct {
   BOOLEAN    Policy2Enabled;
   UINT8      SomeValueArray[SOME_VALUE_ARRAY_MAX_VALUES];
 } STATIC_DATA_SAMPLE_CONTEXT_BUFFER_MODULE;
-
-#endif
diff --git a/PrmPkg/Samples/PrmSampleHardwareAccessModule/Hpet.h b/PrmPkg/Samples/PrmSampleHardwareAccessModule/Hpet.h
index d7298859f6..16364e77a3 100644
--- a/PrmPkg/Samples/PrmSampleHardwareAccessModule/Hpet.h
+++ b/PrmPkg/Samples/PrmSampleHardwareAccessModule/Hpet.h
@@ -12,8 +12,7 @@
 
 **/
 
-#ifndef HPET_REGISTER_H_
-#define HPET_REGISTER_H_
+#pragma once
 
 #define HPET_BASE_ADDRESS  0xFED00000
 #define HPET_RANGE_LENGTH  0x1000
@@ -104,5 +103,3 @@ typedef union {
 } HPET_TIMER_MSI_ROUTE_REGISTER;
 
 #pragma pack()
-
-#endif