diff --git a/src/ca65/lineinfo.c b/src/ca65/lineinfo.c
index c3808cca2..355fdfc75 100644
--- a/src/ca65/lineinfo.c
+++ b/src/ca65/lineinfo.c
@@ -134,7 +134,7 @@ void InitLineInfo (void)
 
 
 
-unsigned AllocLineInfoSlot (unsigned Type, unsigned Count)
+int AllocLineInfoSlot (unsigned Type, unsigned Count)
 /* Allocate a line info slot of the given type and return the slot index */
 {
     /* Grow the array if necessary */
@@ -152,18 +152,18 @@ unsigned AllocLineInfoSlot (unsigned Type, unsigned Count)
     CurLineInfo[UsedSlots].Info = 0;
 
     /* Increment the count and return the index of the new slot */
-    return UsedSlots++;
+    return (int) UsedSlots++;
 }
 
 
 
-void FreeLineInfoSlot (unsigned Slot)
+void FreeLineInfoSlot (int Slot)
 /* Free the line info in the given slot. Note: Alloc/Free must be used in
  * FIFO order.
  */
 {
     /* Check the parameter */
-    PRECONDITION (Slot == UsedSlots - 1);
+    PRECONDITION (Slot == (int) UsedSlots - 1);
 
     /* Free the last entry */
     CurLineInfo[Slot].Info = 0;
@@ -172,7 +172,7 @@ void FreeLineInfoSlot (unsigned Slot)
 
 
 
-void GenLineInfo (unsigned Slot, const FilePos* Pos)
+void GenLineInfo (int Slot, const FilePos* Pos)
 /* Generate a new line info in the given slot */
 {
     /* Get a pointer to the slot */
@@ -190,7 +190,7 @@ void GenLineInfo (unsigned Slot, const FilePos* Pos)
 
 
 
-void ClearLineInfo (unsigned Slot)
+void ClearLineInfo (int Slot)
 /* Clear the line info in the given slot */
 {
     /* Zero the pointer */
diff --git a/src/ca65/lineinfo.h b/src/ca65/lineinfo.h
index 7aa4d1a2f..801a86994 100644
--- a/src/ca65/lineinfo.h
+++ b/src/ca65/lineinfo.h
@@ -56,6 +56,7 @@
  * standard line info. It is assumed to be always there.
  */
 enum {
+    LI_SLOT_INV         = -1,           /* Use to mark invalid slots */
     LI_SLOT_ASM         = 0,            /* Normal assembler source */
     LI_SLOT_EXT         = 1,            /* Externally supplied line info */
 };
@@ -82,18 +83,18 @@ struct LineInfo {
 void InitLineInfo (void);
 /* Initialize the line infos */
 
-unsigned AllocLineInfoSlot (unsigned Type, unsigned Count);
+int AllocLineInfoSlot (unsigned Type, unsigned Count);
 /* Allocate a line info slot of the given type and return the slot index */
 
-void FreeLineInfoSlot (unsigned Slot);
+void FreeLineInfoSlot (int Slot);
 /* Free the line info in the given slot. Note: Alloc/Free must be used in
  * FIFO order.
  */
 
-void GenLineInfo (unsigned Slot, const FilePos* Pos);
+void GenLineInfo (int Slot, const FilePos* Pos);
 /* Generate a new line info in the given slot */
 
-void ClearLineInfo (unsigned Slot);
+void ClearLineInfo (int Slot);
 /* Clear the line info in the given slot */
 
 void GetFullLineInfo (Collection* LineInfos, unsigned IncUsage);
@@ -150,3 +151,4 @@ void WriteLineInfos (void);
 
 
 
+                        
diff --git a/src/ca65/macro.c b/src/ca65/macro.c
index a5c86e9ad..bb5774b19 100644
--- a/src/ca65/macro.c
+++ b/src/ca65/macro.c
@@ -135,7 +135,7 @@ struct MacExp {
     unsigned   	ParamCount;	/* Number of actual parameters */
     TokNode**  	Params;	  	/* List of actual parameters */
     TokNode*   	ParamExp;	/* Node for expanding parameters */
-    unsigned    LISlot;         /* Slot for additional line infos */
+    int         LISlot;         /* Slot for additional line infos */
 };
 
 /* Maximum number of nested macro expansions */
@@ -235,7 +235,7 @@ static void FreeIdDescList (IdDesc* ID)
 /* Free a complete list of IdDesc structures */
 {
     while (ID) {
-        IdDesc* This = ID;      
+        IdDesc* This = ID;
         ID = ID->Next;
         FreeIdDesc (This);
     }
@@ -656,8 +656,8 @@ static int MacExpand (void* Data)
      */
     if (Mac->ParamExp) {
 
-       	/* Ok, use token from parameter list */
-       	TokSet (Mac->ParamExp, Mac->LISlot);
+       	/* Ok, use token from parameter list, but don't use its line info */
+       	TokSet (Mac->ParamExp, LI_SLOT_INV);
 
        	/* Set pointer to next token */
        	Mac->ParamExp = Mac->ParamExp->Next;
diff --git a/src/ca65/toklist.c b/src/ca65/toklist.c
index 44fbd7742..efd5bc105 100644
--- a/src/ca65/toklist.c
+++ b/src/ca65/toklist.c
@@ -82,17 +82,20 @@ void FreeTokNode (TokNode* N)
 
 
 
-void TokSet (TokNode* N, unsigned LineInfoSlot)
-/* Set the scanner token from the given token node. The given line info slot
- * is used to store the position of the token fed into the scanner.
+void TokSet (TokNode* N, int LineInfoSlot)
+/* Set the scanner token from the given token node. If the given line info
+ * slot is not LI_SLOT_INV, it is used to store the position of the token fed
+ * into the scanner.
  */
 {
     /* Set the values */
     CopyToken (&CurTok, &N->T);
     SB_Terminate (&CurTok.SVal);
 
-    /* Set the position */
-    GenLineInfo (LineInfoSlot, &CurTok.Pos);
+    /* Set the position if the slot is not invald */
+    if (LineInfoSlot != LI_SLOT_INV) {
+        GenLineInfo (LineInfoSlot, &CurTok.Pos);
+    }
 }
 
 
diff --git a/src/ca65/toklist.h b/src/ca65/toklist.h
index 18a9c42f9..145c5f25a 100644
--- a/src/ca65/toklist.h
+++ b/src/ca65/toklist.h
@@ -95,9 +95,10 @@ TokNode* NewTokNode (void);
 void FreeTokNode (TokNode* N);
 /* Free the given token node */
 
-void TokSet (TokNode* N, unsigned LineInfoSlot);
-/* Set the scanner token from the given token node. The given line info slot
- * is used to store the position of the token fed into the scanner.
+void TokSet (TokNode* N, int LineInfoSlot);
+/* Set the scanner token from the given token node. If the given line info
+ * slot is not LI_SLOT_INV, it is used to store the position of the token fed
+ * into the scanner.
  */
 
 enum TC TokCmp (const TokNode* N);