3 files changed, 15 insertions, 5 deletions
diff --git a/ext/fiddle/closure.c b/ext/fiddle/closure.c
index 5f55d6d4f8..48520997bc 100644
--- a/ext/fiddle/closure.c
+++ b/ext/fiddle/closure.c
@@ -110,14 +110,13 @@ callback(ffi_cif *cif, void *resp, void **args, void *ctx)
 	*(long *)resp = NUM2LONG(ret);
 	break;
       case TYPE_CHAR:
-	*(char *)resp = NUM2INT(ret);
+      case TYPE_SHORT:
+      case TYPE_INT:
+	*(ffi_sarg *)resp = NUM2INT(ret);
 	break;
       case TYPE_VOIDP:
 	*(void **)resp = NUM2PTR(ret);
 	break;
-      case TYPE_INT:
-	*(int *)resp = NUM2INT(ret);
-	break;
       case TYPE_DOUBLE:
 	*(double *)resp = NUM2DBL(ret);
 	break;
diff --git a/ext/fiddle/conversions.c b/ext/fiddle/conversions.c
index bb5361a6c8..8ffd7c5e08 100644
--- a/ext/fiddle/conversions.c
+++ b/ext/fiddle/conversions.c
@@ -56,7 +56,11 @@ value_to_generic(int type, VALUE src, fiddle_generic * dst)
 	dst->pointer = NUM2PTR(rb_Integer(src));
 	break;
       case TYPE_CHAR:
+	dst->schar = NUM2INT(src);
+	break;
       case TYPE_SHORT:
+	dst->sshort = NUM2INT(src);
+	break;
       case TYPE_INT:
 	dst->sint = NUM2INT(src);
 	break;
@@ -103,9 +107,14 @@ generic_to_value(VALUE rettype, fiddle_generic retval)
         return rb_funcall(cPointer, rb_intern("[]"), 1,
           PTR2NUM((void *)retval.pointer));
       case TYPE_CHAR:
+	if (signed_p) return INT2NUM((char)retval.fffi_sarg);
+	return INT2NUM((unsigned char)retval.fffi_arg);
       case TYPE_SHORT:
+	if (signed_p) return INT2NUM((short)retval.fffi_sarg);
+	return INT2NUM((unsigned short)retval.fffi_arg);
       case TYPE_INT:
-	return INT2NUM(retval.sint);
+	if (signed_p) return INT2NUM((int)retval.fffi_sarg);
+	return UINT2NUM((unsigned int)retval.fffi_arg);
       case TYPE_LONG:
 	if (signed_p) return LONG2NUM(retval.slong);
 	return ULONG2NUM(retval.ulong);
diff --git a/ext/fiddle/conversions.h b/ext/fiddle/conversions.h
index eb16125908..5a605b3945 100644
--- a/ext/fiddle/conversions.h
+++ b/ext/fiddle/conversions.h
@@ -5,6 +5,8 @@
 
 typedef union
 {
+    ffi_arg  fffi_arg;     /* rvalue smaller than unsigned long */
+    ffi_sarg fffi_sarg;    /* rvalue smaller than signed long */
     unsigned char uchar;   /* ffi_type_uchar */
     signed char   schar;   /* ffi_type_schar */
     unsigned short ushort; /* ffi_type_sshort */