diff --git a/DfciPkg/Include/Library/DfciAssetTagSettingLib.h b/DfciPkg/Include/Library/DfciAssetTagSettingLib.h
index aaa670bb..7fe3ea20 100644
--- a/DfciPkg/Include/Library/DfciAssetTagSettingLib.h
+++ b/DfciPkg/Include/Library/DfciAssetTagSettingLib.h
@@ -8,6 +8,9 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
 
 **/
 
+#ifndef DFCI_ASSET_TAG_SETTING_LIB_H_
+#define DFCI_ASSET_TAG_SETTING_LIB_H_
+
 /**
  * Settings Provider AssetTagGet routine for pre SettingsManager access.
  *
@@ -25,3 +28,5 @@ DfciGetAssetTag (
   IN  OUT   UINTN  *ValueSize,
   OUT       VOID   *Value
   );
+
+#endif
diff --git a/DfciPkg/Include/Library/DfciGroupLib.h b/DfciPkg/Include/Library/DfciGroupLib.h
index f238874d..f1a7dba9 100644
--- a/DfciPkg/Include/Library/DfciGroupLib.h
+++ b/DfciPkg/Include/Library/DfciGroupLib.h
@@ -8,6 +8,9 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
 
 **/
 
+#ifndef DFCI_GROUP_LIB_H_
+#define DFCI_GROUP_LIB_H_
+
 typedef struct {
   DFCI_SETTING_ID_STRING    GroupId;               // Pointer to Group Id
   DFCI_SETTING_ID_STRING    *GroupMembers;         // Pointer to array of Setting Id's
@@ -26,3 +29,5 @@ EFIAPI
 DfciGetGroupEntries (
   VOID
   );
+
+#endif
diff --git a/DfciPkg/Include/Library/DfciSettingChangedNotificationLib.h b/DfciPkg/Include/Library/DfciSettingChangedNotificationLib.h
index 6b357bdc..a654737f 100644
--- a/DfciPkg/Include/Library/DfciSettingChangedNotificationLib.h
+++ b/DfciPkg/Include/Library/DfciSettingChangedNotificationLib.h
@@ -8,6 +8,9 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
 
 **/
 
+#ifndef DFCI_SETTING_CHANGED_NOTIFICATION_LIB_H_
+#define DFCI_SETTING_CHANGED_NOTIFICATION_LIB_H_
+
 /**
  * Process Setting Changed    - Called for any setting that has changed.  Not called when a setting
  *                              has not changed.  The setting value is also supplied.
@@ -48,3 +51,5 @@ EFIAPI
 DfciSettingChangedResetNotification (
   VOID
   );
+
+#endif
diff --git a/DfciPkg/Include/Library/DfciV1SupportLib.h b/DfciPkg/Include/Library/DfciV1SupportLib.h
index 6d939914..9e81544f 100644
--- a/DfciPkg/Include/Library/DfciV1SupportLib.h
+++ b/DfciPkg/Include/Library/DfciV1SupportLib.h
@@ -8,6 +8,9 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
 
 **/
 
+#ifndef DFCI_V1_SUPPORT_LIB_H_
+#define DFCI_V1_SUPPORT_LIB_H_
+
 /**
  * Return V2 string from V1 Id String
  *
@@ -49,3 +52,5 @@ EFIAPI
 DfciV1NumberFromId (
   DFCI_SETTING_ID_STRING  Id
   );
+
+#endif