diff --git a/redfish-core/include/utils/pcie_util.hpp b/redfish-core/include/utils/pcie_util.hpp
index d9e8480..4db6e03 100644
--- a/redfish-core/include/utils/pcie_util.hpp
+++ b/redfish-core/include/utils/pcie_util.hpp
@@ -123,11 +123,10 @@
     if (slotType ==
         "xyz.openbmc_project.Inventory.Item.PCIeSlot.SlotTypes.Unknown")
     {
-        return pcie_slots::SlotTypes::Invalid;
+        return std::nullopt;
     }
 
-    // Unspecified slotType should return an internal error.
-    return std::nullopt;
+    return pcie_slots::SlotTypes::Invalid;
 }
 
 inline std::optional<pcie_device::PCIeTypes>
@@ -162,11 +161,10 @@
         generationInUse ==
             "xyz.openbmc_project.Inventory.Item.PCIeSlot.Generations.Unknown")
     {
-        return pcie_device::PCIeTypes::Invalid;
+        return std::nullopt;
     }
 
-    // The value is not unknown or Gen1-5, need return an internal error.
-    return std::nullopt;
+    return pcie_device::PCIeTypes::Invalid;
 }
 
 } // namespace pcie_util
diff --git a/redfish-core/lib/pcie.hpp b/redfish-core/lib/pcie.hpp
index b63c850..82e1a5f 100644
--- a/redfish-core/lib/pcie.hpp
+++ b/redfish-core/lib/pcie.hpp
@@ -295,11 +295,18 @@
 
         if (!redfishGenerationInUse)
         {
-            messages::internalError(resp);
-            return;
+            BMCWEB_LOG_WARNING << "Unknown PCIe Device Generation: "
+                               << *generationInUse;
         }
-        if (*redfishGenerationInUse != pcie_device::PCIeTypes::Invalid)
+        else
         {
+            if (*redfishGenerationInUse == pcie_device::PCIeTypes::Invalid)
+            {
+                BMCWEB_LOG_ERROR << "Invalid PCIe Device Generation: "
+                                 << *generationInUse;
+                messages::internalError(resp);
+                return;
+            }
             resp.jsonValue["PCIeInterface"]["PCIeType"] =
                 *redfishGenerationInUse;
         }
diff --git a/redfish-core/lib/pcie_slots.hpp b/redfish-core/lib/pcie_slots.hpp
index 7246aea..62fef3e 100644
--- a/redfish-core/lib/pcie_slots.hpp
+++ b/redfish-core/lib/pcie_slots.hpp
@@ -69,11 +69,16 @@
             pcie_util::redfishPcieGenerationFromDbus(*generation);
         if (!pcieType)
         {
-            messages::internalError(asyncResp->res);
-            return;
+            BMCWEB_LOG_WARNING << "Unknown PCIe Slot Generation: "
+                               << *generation;
         }
-        if (*pcieType != pcie_device::PCIeTypes::Invalid)
+        else
         {
+            if (*pcieType == pcie_device::PCIeTypes::Invalid)
+            {
+                messages::internalError(asyncResp->res);
+                return;
+            }
             slot["PCIeType"] = *pcieType;
         }
     }
@@ -89,11 +94,16 @@
             pcie_util::dbusSlotTypeToRf(*slotType);
         if (!redfishSlotType)
         {
-            messages::internalError(asyncResp->res);
-            return;
+            BMCWEB_LOG_WARNING << "Unknown PCIe Slot Type: " << *slotType;
         }
-        if (*redfishSlotType != pcie_slots::SlotTypes::Invalid)
+        else
         {
+            if (*redfishSlotType == pcie_slots::SlotTypes::Invalid)
+            {
+                BMCWEB_LOG_ERROR << "Unknown PCIe Slot Type: " << *slotType;
+                messages::internalError(asyncResp->res);
+                return;
+            }
             slot["SlotType"] = *redfishSlotType;
         }
     }