diff --git a/Utilities/ocvalidate/README.md b/Utilities/ocvalidate/README.md
index 562ba6d7..4dae61cf 100644
--- a/Utilities/ocvalidate/README.md
+++ b/Utilities/ocvalidate/README.md
@@ -81,6 +81,7 @@ Utility to validate whether a `config.plist` matches requirements and convention
 #### Generic
 - SystemProductName: Only real Mac models are accepted.
 - SystemMemoryStatus: Only `Auto`, `Upgradable`, or `Soldered` are accepted.
+- ProcessorType: Only known first byte can be set.
 
 ### UEFI
 #### APFS
diff --git a/Utilities/ocvalidate/ValidatePlatformInfo.c b/Utilities/ocvalidate/ValidatePlatformInfo.c
index 50a0e271..58720bb4 100644
--- a/Utilities/ocvalidate/ValidatePlatformInfo.c
+++ b/Utilities/ocvalidate/ValidatePlatformInfo.c
@@ -17,6 +17,47 @@
 #include "OcValidateLib.h"
 
 #include <Library/OcMacInfoLib.h>
+#include <IndustryStandard/AppleSmBios.h>
+
+STATIC
+BOOLEAN
+ValidateProcessorType (
+  IN  UINT16  ProcessorType
+  )
+{
+  UINTN  Index;
+  UINT8  AllowedProcessorType[] = {
+    AppleProcessorMajorCore,
+    AppleProcessorMajorCore2,
+    AppleProcessorMajorXeonPenryn,
+    AppleProcessorMajorXeonNehalem,
+    AppleProcessorMajorI5,
+    AppleProcessorMajorI7,
+    AppleProcessorMajorI3,
+    AppleProcessorMajorI9,
+    AppleProcessorMajorXeonE5,
+    AppleProcessorMajorM,
+    AppleProcessorMajorM3,
+    AppleProcessorMajorM5,
+    AppleProcessorMajorM7,
+    AppleProcessorMajorXeonW
+  };
+
+  //
+  // 0 is allowed.
+  //
+  if (ProcessorType == 0U) {
+    return TRUE;
+  }
+
+  for (Index = 0; Index < ARRAY_SIZE (AllowedProcessorType); ++Index) {
+    if ((ProcessorType >> 8U) == AllowedProcessorType[Index]) {
+      return TRUE;
+    }
+  }
+
+  return FALSE;
+}
 
 //
 // NOTE: Only PlatformInfo->Generic is checked here. The rest is ignored.
@@ -33,6 +74,7 @@ CheckPlatformInfoGeneric (
   CONST CHAR8         *SystemProductName;
   CONST CHAR8         *SystemMemoryStatus;
   CONST CHAR8         *AsciiSystemUUID;
+  UINT16              ProcessorType;
 
   ErrorCount          = 0;
   UserPlatformInfo    = &Config->PlatformInfo;
@@ -57,6 +99,12 @@ CheckPlatformInfoGeneric (
     ++ErrorCount;
   }
 
+  ProcessorType       = UserPlatformInfo->Generic.ProcessorType;
+  if (!ValidateProcessorType (ProcessorType)) {
+    DEBUG ((DEBUG_WARN, "PlatformInfo->Generic->ProcessorType is borked!\n"));
+    ++ErrorCount;
+  }
+
   //
   // TODO: Sanitise MLB, ProcessorType, and SystemSerialNumber if possible...
   //