diff --git a/SPDAccessor/SPDAccessor.cpp b/SPDAccessor/SPDAccessor.cpp
index 1c5b302d4..91b40fbcb 100644
--- a/SPDAccessor/SPDAccessor.cpp
+++ b/SPDAccessor/SPDAccessor.cpp
@@ -66,7 +66,8 @@ const char *spd_memory_type_name[] =
     "LPDDR4",
     "LPDDR4X",
     "DDR5",
-    "LPDDR5"
+    "LPDDR5",
+    "Unknown"
 };
 
 SPDAccessor::SPDAccessor(i2c_smbus_interface *bus, uint8_t spd_addr)
@@ -161,7 +162,16 @@ DDR4Accessor::~DDR4Accessor()
 
 SPDMemoryType DDR4Accessor::memory_type()
 {
-    return((SPDMemoryType)(this->at(BASIC_MEMORY_TYPE_ADDR)));
+    SPDMemoryType type = (SPDMemoryType)(this->at(BASIC_MEMORY_TYPE_ADDR));
+
+    if(type <= SPD_UNKNOWN)
+    {
+        return(type);
+    }
+    else
+    {
+        return(SPD_UNKNOWN);
+    }
 }
 
 uint16_t DDR4Accessor::jedec_id()
@@ -195,7 +205,16 @@ DDR5Accessor::~DDR5Accessor()
 
 SPDMemoryType DDR5Accessor::memory_type()
 {
-    return((SPDMemoryType)(this->at(BASIC_MEMORY_TYPE_ADDR)));
+    SPDMemoryType type = (SPDMemoryType)(this->at(BASIC_MEMORY_TYPE_ADDR));
+
+    if(type <= SPD_UNKNOWN)
+    {
+        return(type);
+    }
+    else
+    {
+        return(SPD_UNKNOWN);
+    }
 }
 
 uint16_t DDR5Accessor::jedec_id()
diff --git a/SPDAccessor/SPDCommon.h b/SPDAccessor/SPDCommon.h
index 12538fdab..b7111c482 100644
--- a/SPDAccessor/SPDCommon.h
+++ b/SPDAccessor/SPDCommon.h
@@ -48,7 +48,8 @@ typedef enum
     SPD_LPDDR4_SDRAM  = 16,
     SPD_LPDDR4X_SDRAM = 17,
     SPD_DDR5_SDRAM    = 18,
-    SPD_LPDDR5_SDRAM  = 19
+    SPD_LPDDR5_SDRAM  = 19,
+    SPD_UNKNOWN       = 20,
 } SPDMemoryType;
 
 #define SPD_IO_DELAY   1ms
diff --git a/SPDAccessor/SPDDetector.cpp b/SPDAccessor/SPDDetector.cpp
index 29bb60b71..fcb7b2e0e 100644
--- a/SPDAccessor/SPDDetector.cpp
+++ b/SPDAccessor/SPDDetector.cpp
@@ -30,7 +30,14 @@ bool SPDDetector::is_valid() const
 
 SPDMemoryType SPDDetector::memory_type() const
 {
-    return(mem_type);
+    if(mem_type <= SPD_UNKNOWN)
+    {
+        return(mem_type);
+    }
+    else
+    {
+        return(SPD_UNKNOWN);
+    }
 }
 
 void SPDDetector::detect_memory_type()
diff --git a/SPDAccessor/SPDWrapper.cpp b/SPDAccessor/SPDWrapper.cpp
index 5c4e321a5..32ecd2d8f 100644
--- a/SPDAccessor/SPDWrapper.cpp
+++ b/SPDAccessor/SPDWrapper.cpp
@@ -65,7 +65,14 @@ SPDWrapper::~SPDWrapper()
 
 SPDMemoryType SPDWrapper::memory_type()
 {
-    return mem_type;
+    if(mem_type <= SPD_UNKNOWN)
+    {
+        return(mem_type);
+    }
+    else
+    {
+        return(SPD_UNKNOWN);
+    }
 }
 
 uint8_t SPDWrapper::address()