diff --git a/include/xbps_api_impl.h b/include/xbps_api_impl.h
index 8d3a9aa9..ab5422ab 100644
--- a/include/xbps_api_impl.h
+++ b/include/xbps_api_impl.h
@@ -53,7 +53,7 @@
 #define FEXTRACT_FLAGS	ARCHIVE_EXTRACT_OWNER | EXTRACT_FLAGS
 
 #ifndef __UNCONST
-#define __UNCONST(a)	((void *)(unsigned long)(const void *)(a))
+#define __UNCONST(a)	((void *)(uintptr_t)(const void *)(a))
 #endif
 
 /* libarchive compat */
diff --git a/lib/fetch/common.h b/lib/fetch/common.h
index 3fde522c..647b184b 100644
--- a/lib/fetch/common.h
+++ b/lib/fetch/common.h
@@ -168,7 +168,7 @@ fetchIO		*ftp_request(struct url *, const char *, const char *,
 #define CHECK_FLAG(x)	(flags && strchr(flags, (x)))
 
 #ifndef __UNCONST
-#define __UNCONST(a)    ((void *)(unsigned long)(const void *)(a))
+#define __UNCONST(a)    ((void *)(uintptr_t)(const void *)(a))
 #endif
 
 #endif