diff --git a/libyasm/arch.h b/libyasm/arch.h
index ece57e1b..48f04aad 100644
--- a/libyasm/arch.h
+++ b/libyasm/arch.h
@@ -40,9 +40,9 @@ struct arch {
 	void (*bc_print) (FILE *f, const bytecode *bc);
 
 	/* See bytecode.h comments on bc_calc_len() */
-	int (*bc_calc_len) (bytecode *bc, /*@only@*/ /*@null@*/
-			    intnum *(*resolve_label) (section *sect, /*@null@*/
-						      bytecode *bc));
+	unsigned long (*bc_calc_len) (bytecode *bc, /*@only@*/ /*@null@*/
+				      intnum *(*resolve_label) (section *sect,
+					  /*@null@*/ bytecode *bc));
     } bc;
 };
 
diff --git a/libyasm/bytecode.c b/libyasm/bytecode.c
index c35a71d6..225966ca 100644
--- a/libyasm/bytecode.c
+++ b/libyasm/bytecode.c
@@ -307,7 +307,7 @@ bc_print(FILE *f, const bytecode *bc)
     fprintf(f, "%*sOffset=%lx\n", indent_level, "", bc->offset);
 }
 
-int
+unsigned long
 bc_calc_len(bytecode *bc,
 	    intnum *(*resolve_label) (section *sect, /*@null@*/ bytecode *bc))
 {
diff --git a/libyasm/bytecode.h b/libyasm/bytecode.h
index e8607c12..3cb06718 100644
--- a/libyasm/bytecode.h
+++ b/libyasm/bytecode.h
@@ -63,9 +63,9 @@ void bc_print(FILE *f, const bytecode *bc);
  * resolve_label is the function used to determine the value (offset) of a
  *  in-file label (eg, not an EXTERN variable, which is indeterminate).
  */
-int bc_calc_len(bytecode *bc, /*@only@*/ /*@null@*/
-		intnum *(*resolve_label) (section *sect,
-					  /*@null@*/ bytecode *bc));
+unsigned long bc_calc_len(bytecode *bc, /*@only@*/ /*@null@*/
+			  intnum *(*resolve_label) (section *sect,
+						    /*@null@*/ bytecode *bc));
 
 /* void bcs_initialize(bytecodehead *headp); */
 #define	bcs_initialize(headp)	STAILQ_INIT(headp)
diff --git a/modules/arch/x86/x86-int.h b/modules/arch/x86/x86-int.h
index a75c9995..f8d79ed5 100644
--- a/modules/arch/x86/x86-int.h
+++ b/modules/arch/x86/x86-int.h
@@ -96,9 +96,9 @@ typedef struct x86_jmprel {
 
 void x86_bc_delete(bytecode *bc);
 void x86_bc_print(FILE *f, const bytecode *bc);
-int x86_bc_calc_len(bytecode *bc, /*@only@*/ /*@null@*/
-		    intnum *(*resolve_label) (section *sect,
-					      /*@null@*/ bytecode *bc));
+unsigned long x86_bc_calc_len(bytecode *bc, /*@only@*/ /*@null@*/
+			      intnum *(*resolve_label) (section *sect,
+				  /*@null@*/ bytecode *bc));
 
 int x86_expr_checkea(expr **ep, unsigned char *addrsize, unsigned char bits,
 		     unsigned char nosplit, unsigned char *displen,
diff --git a/modules/arch/x86/x86bc.c b/modules/arch/x86/x86bc.c
index a4237713..2f1602da 100644
--- a/modules/arch/x86/x86bc.c
+++ b/modules/arch/x86/x86bc.c
@@ -460,7 +460,7 @@ x86_bc_print(FILE *f, const bytecode *bc)
     }
 }
 
-static int
+static unsigned long
 x86_bc_calc_len_insn(x86_insn *insn, /*@only@*/ /*@null@*/
 		     intnum *(*resolve_label) (section *sect,
 					       /*@null@*/ bytecode *bc))
@@ -518,7 +518,7 @@ x86_bc_calc_len_insn(x86_insn *insn, /*@only@*/ /*@null@*/
     return 0;
 }
 
-int
+unsigned long
 x86_bc_calc_len(bytecode *bc,
 		intnum *(*resolve_label) (section *sect,
 					  /*@null@*/ bytecode *bc))
diff --git a/src/arch.h b/src/arch.h
index ece57e1b..48f04aad 100644
--- a/src/arch.h
+++ b/src/arch.h
@@ -40,9 +40,9 @@ struct arch {
 	void (*bc_print) (FILE *f, const bytecode *bc);
 
 	/* See bytecode.h comments on bc_calc_len() */
-	int (*bc_calc_len) (bytecode *bc, /*@only@*/ /*@null@*/
-			    intnum *(*resolve_label) (section *sect, /*@null@*/
-						      bytecode *bc));
+	unsigned long (*bc_calc_len) (bytecode *bc, /*@only@*/ /*@null@*/
+				      intnum *(*resolve_label) (section *sect,
+					  /*@null@*/ bytecode *bc));
     } bc;
 };
 
diff --git a/src/arch/x86/x86-int.h b/src/arch/x86/x86-int.h
index a75c9995..f8d79ed5 100644
--- a/src/arch/x86/x86-int.h
+++ b/src/arch/x86/x86-int.h
@@ -96,9 +96,9 @@ typedef struct x86_jmprel {
 
 void x86_bc_delete(bytecode *bc);
 void x86_bc_print(FILE *f, const bytecode *bc);
-int x86_bc_calc_len(bytecode *bc, /*@only@*/ /*@null@*/
-		    intnum *(*resolve_label) (section *sect,
-					      /*@null@*/ bytecode *bc));
+unsigned long x86_bc_calc_len(bytecode *bc, /*@only@*/ /*@null@*/
+			      intnum *(*resolve_label) (section *sect,
+				  /*@null@*/ bytecode *bc));
 
 int x86_expr_checkea(expr **ep, unsigned char *addrsize, unsigned char bits,
 		     unsigned char nosplit, unsigned char *displen,
diff --git a/src/arch/x86/x86bc.c b/src/arch/x86/x86bc.c
index a4237713..2f1602da 100644
--- a/src/arch/x86/x86bc.c
+++ b/src/arch/x86/x86bc.c
@@ -460,7 +460,7 @@ x86_bc_print(FILE *f, const bytecode *bc)
     }
 }
 
-static int
+static unsigned long
 x86_bc_calc_len_insn(x86_insn *insn, /*@only@*/ /*@null@*/
 		     intnum *(*resolve_label) (section *sect,
 					       /*@null@*/ bytecode *bc))
@@ -518,7 +518,7 @@ x86_bc_calc_len_insn(x86_insn *insn, /*@only@*/ /*@null@*/
     return 0;
 }
 
-int
+unsigned long
 x86_bc_calc_len(bytecode *bc,
 		intnum *(*resolve_label) (section *sect,
 					  /*@null@*/ bytecode *bc))
diff --git a/src/bytecode.c b/src/bytecode.c
index c35a71d6..225966ca 100644
--- a/src/bytecode.c
+++ b/src/bytecode.c
@@ -307,7 +307,7 @@ bc_print(FILE *f, const bytecode *bc)
     fprintf(f, "%*sOffset=%lx\n", indent_level, "", bc->offset);
 }
 
-int
+unsigned long
 bc_calc_len(bytecode *bc,
 	    intnum *(*resolve_label) (section *sect, /*@null@*/ bytecode *bc))
 {
diff --git a/src/bytecode.h b/src/bytecode.h
index e8607c12..3cb06718 100644
--- a/src/bytecode.h
+++ b/src/bytecode.h
@@ -63,9 +63,9 @@ void bc_print(FILE *f, const bytecode *bc);
  * resolve_label is the function used to determine the value (offset) of a
  *  in-file label (eg, not an EXTERN variable, which is indeterminate).
  */
-int bc_calc_len(bytecode *bc, /*@only@*/ /*@null@*/
-		intnum *(*resolve_label) (section *sect,
-					  /*@null@*/ bytecode *bc));
+unsigned long bc_calc_len(bytecode *bc, /*@only@*/ /*@null@*/
+			  intnum *(*resolve_label) (section *sect,
+						    /*@null@*/ bytecode *bc));
 
 /* void bcs_initialize(bytecodehead *headp); */
 #define	bcs_initialize(headp)	STAILQ_INIT(headp)