diff --git a/engines/sci/engine/kernel.cpp b/engines/sci/engine/kernel.cpp
index 1fd80d2cf78..fb2c60cdb6d 100644
--- a/engines/sci/engine/kernel.cpp
+++ b/engines/sci/engine/kernel.cpp
@@ -685,6 +685,9 @@ int Kernel::findRegType(reg_t reg) {
 	if (!reg.segment)
 		return reg.offset ? KSIG_ARITHMETIC : KSIG_ARITHMETIC | KSIG_NULL;
 
+	if (reg.segment == 0xFFFF)
+		return KSIG_UNINITIALIZED;
+
 	// Otherwise it's an object
 	SegmentObj *mobj = _segMan->getSegmentObj(reg.segment);
 	if (!mobj)
@@ -728,13 +731,14 @@ struct SignatureDebugType {
 };
 
 static const SignatureDebugType signatureDebugTypeList[] = {
-	{ KSIG_NULL,       "null" },
-	{ KSIG_ARITHMETIC, "value" },
-	{ KSIG_OBJECT,     "object" },
-	{ KSIG_REF,        "reference" },
-	{ KSIG_LIST,       "list" },
-	{ KSIG_NODE,       "node" },
-	{ 0,               NULL }
+	{ KSIG_NULL,          "null" },
+	{ KSIG_ARITHMETIC,    "value" },
+	{ KSIG_UNINITIALIZED, "uninitialized" },
+	{ KSIG_OBJECT,        "object" },
+	{ KSIG_REF,           "reference" },
+	{ KSIG_LIST,          "list" },
+	{ KSIG_NODE,          "node" },
+	{ 0,                  NULL }
 };
 
 static void kernelSignatureDebugType(const char type) {
diff --git a/engines/sci/engine/kernel.h b/engines/sci/engine/kernel.h
index cb66aa9f4d4..9b4a11f1321 100644
--- a/engines/sci/engine/kernel.h
+++ b/engines/sci/engine/kernel.h
@@ -99,14 +99,15 @@ struct SelectorCache;	// from selector.h
 
 // Compiled signatures
 enum {
-	KSIG_LIST       = 0x01,
-	KSIG_NODE       = 0x02,
-	KSIG_OBJECT     = 0x04,
-	KSIG_REF        = 0x08,
-	KSIG_ARITHMETIC = 0x10,
-	KSIG_NULL       = 0x40,
-	KSIG_ANY        = 0x5f,
-	KSIG_ELLIPSIS   = 0x80
+	KSIG_LIST          = 0x01,
+	KSIG_NODE          = 0x02,
+	KSIG_OBJECT        = 0x04,
+	KSIG_REF           = 0x08,
+	KSIG_ARITHMETIC    = 0x10,
+	KSIG_UNINITIALIZED = 0x20,
+	KSIG_NULL          = 0x40,
+	KSIG_ANY           = 0x5f,
+	KSIG_ELLIPSIS      = 0x80
 };
 
 // ----------------------------------------------------------------------------