diff --git a/src/cc65/coptind.c b/src/cc65/coptind.c
index 24bc260db..ddd78a325 100644
--- a/src/cc65/coptind.c
+++ b/src/cc65/coptind.c
@@ -673,7 +673,7 @@ unsigned OptDuplicateLoads (CodeSeg* S)
 	    case OP65_LDA:
 	        if (E->RI->In.RegA >= 0               && /* Value of A is known */
        		    CE_KnownImm (E)                   && /* Value to be loaded is known */
-       	       	    E->RI->In.RegA == E->Num          && /* Both are equal */
+       	       	    E->RI->In.RegA == (long) E->Num   && /* Both are equal */
        	       	    (N = CS_GetNextEntry (S, I)) != 0 && /* There is a next entry */
 		    (N->Info & OF_FBRA) == 0) {	       	 /* Which is not a cond branch */
 		    Delete = 1;
@@ -683,7 +683,7 @@ unsigned OptDuplicateLoads (CodeSeg* S)
 	    case OP65_LDX:
        	        if (E->RI->In.RegX >= 0               && /* Value of X is known */
 		    CE_KnownImm (E)                   && /* Value to be loaded is known */
-		    E->RI->In.RegX == E->Num          && /* Both are equal */
+		    E->RI->In.RegX == (long) E->Num   && /* Both are equal */
        	       	    (N = CS_GetNextEntry (S, I)) != 0 && /* There is a next entry */
 		    (N->Info & OF_FBRA) == 0) {	       	 /* Which is not a cond branch */
 		    Delete = 1;
@@ -693,7 +693,7 @@ unsigned OptDuplicateLoads (CodeSeg* S)
 	    case OP65_LDY:
        	        if (E->RI->In.RegY >= 0               && /* Value of Y is known */
 		    CE_KnownImm (E)                   && /* Value to be loaded is known */
-		    E->RI->In.RegY == E->Num          && /* Both are equal */
+		    E->RI->In.RegY == (long) E->Num   && /* Both are equal */
        	       	    (N = CS_GetNextEntry (S, I)) != 0 && /* There is a next entry */
 		    (N->Info & OF_FBRA) == 0) {	       	 /* Which is not a cond branch */
 		    Delete = 1;
@@ -900,11 +900,11 @@ unsigned OptTransfers (CodeSeg* S)
 			goto NextEntry;
 		    }
 		}
-    
+
 		/* Remove both transfers */
 		CS_DelEntry (S, I+1);
 		CS_DelEntry (S, I);
-    
+
 		/* Remember, we had changes */
 		++Changes;
 	    }
diff --git a/src/cc65/expr.c b/src/cc65/expr.c
index 525651945..a26935902 100644
--- a/src/cc65/expr.c
+++ b/src/cc65/expr.c
@@ -411,7 +411,7 @@ static int kcalc (int tok, long val1, long val2)
 
 
 
-static GenDesc* FindGen (int Tok, GenDesc** Table)
+static GenDesc* FindGen (token_t Tok, GenDesc** Table)
 {
     GenDesc* G;
     while ((G = *Table) != 0) {
diff --git a/src/cc65/exprnode.c b/src/cc65/exprnode.c
index a5cf4aef1..8bffe688f 100644
--- a/src/cc65/exprnode.c
+++ b/src/cc65/exprnode.c
@@ -92,7 +92,7 @@ void SetItem (ExprNode* N, void* Item, unsigned Index)
 {
     if (Index >= CollCount (&N->List)) {
 	/* Fill up with NULL pointers */
-       	while (Index >= CollCount (&N->List) < Index) {
+       	while (Index >= CollCount (&N->List)) {
 	    CollAppend (&N->List, 0);
 	}
 	/* Append the new item */
diff --git a/src/cc65/make/gcc.mak b/src/cc65/make/gcc.mak
index 5facfeaaa..fb5478529 100644
--- a/src/cc65/make/gcc.mak
+++ b/src/cc65/make/gcc.mak
@@ -14,7 +14,7 @@ COMMON	= ../common
 
 # Default for the compiler lib search path as compiler define
 CDEFS=-DCC65_INC=\"/usr/lib/cc65/include/\"
-CFLAGS = -O2 -g -Wall -I$(COMMON) $(CDEFS)
+CFLAGS = -O2 -g -Wall -W -Wno-unused-parameter -I$(COMMON) $(CDEFS)
 CC=gcc
 EBIND=emxbind
 LDFLAGS=
diff --git a/src/cc65/preproc.c b/src/cc65/preproc.c
index c95bbb92c..8922c7733 100644
--- a/src/cc65/preproc.c
+++ b/src/cc65/preproc.c
@@ -314,7 +314,7 @@ static void ExpandMacroArgs (Macro* M)
 static int MacroCall (Macro* M)
 /* Process a function like macro */
 {
-    unsigned  	ArgCount;      	/* Macro argument count */
+    int         ArgCount;      	/* Macro argument count */
     unsigned 	ParCount;       /* Number of open parenthesis */
     char     	Buf[LINESIZE];	/* Argument buffer */
     const char* ArgStart;
@@ -355,7 +355,7 @@ static int MacroCall (Macro* M)
     	      	if (ArgCount < M->ArgCount) {
     	      	    M->ActualArgs[ArgCount++] = ArgStart;
        	       	} else if (CurC != ')' || *ArgStart != '\0' || M->ArgCount > 0) {
- 	    	    /* Be sure not to count the single empty argument for a
+ 	       	    /* Be sure not to count the single empty argument for a
  	    	     * macro that does not have arguments.
  	    	     */
     	      	    ++ArgCount;