Index: libcfa/src/concurrency/coroutine.cfa
===================================================================
--- libcfa/src/concurrency/coroutine.cfa	(revision 8fc9a5fcdfcbc515e3c551f072da9656d0800e52)
+++ libcfa/src/concurrency/coroutine.cfa	(revision 290553a54a5500f937216fcdee0d5dab8d5826bc)
@@ -92,5 +92,5 @@
 
 // minimum feasible stack size in bytes
-#define MinStackSize 1000
+static const size_t MinStackSize = 1000;
 extern size_t __page_size;				// architecture pagesize HACK, should go in proper runtime singleton
 
Index: libcfa/src/concurrency/io/call.cfa.in
===================================================================
--- libcfa/src/concurrency/io/call.cfa.in	(revision 8fc9a5fcdfcbc515e3c551f072da9656d0800e52)
+++ libcfa/src/concurrency/io/call.cfa.in	(revision 290553a54a5500f937216fcdee0d5dab8d5826bc)
@@ -47,37 +47,30 @@
 	#include "kernel/fwd.hfa"
 
-	#if defined(CFA_HAVE_IOSQE_FIXED_FILE) && defined(CFA_HAVE_IOSQE_IO_DRAIN) && defined(CFA_HAVE_IOSQE_ASYNC)
-		#define REGULAR_FLAGS (IOSQE_FIXED_FILE | IOSQE_IO_DRAIN | IOSQE_ASYNC)
-	#elif defined(CFA_HAVE_IOSQE_FIXED_FILE) && defined(CFA_HAVE_IOSQE_ASYNC)
-		#define REGULAR_FLAGS (IOSQE_FIXED_FILE | IOSQE_ASYNC)
-	#elif defined(CFA_HAVE_IOSQE_FIXED_FILE) && defined(CFA_HAVE_IOSQE_IO_DRAIN)
-		#define REGULAR_FLAGS (IOSQE_FIXED_FILE | IOSQE_IO_DRAIN)
-	#elif defined(CFA_HAVE_IOSQE_IO_DRAIN) && defined(CFA_HAVE_IOSQE_ASYNC)
-		#define REGULAR_FLAGS (IOSQE_IO_DRAIN | IOSQE_ASYNC)
-	#elif defined(CFA_HAVE_IOSQE_FIXED_FILE)
-		#define REGULAR_FLAGS (IOSQE_FIXED_FILE)
-	#elif defined(CFA_HAVE_IOSQE_IO_DRAIN)
-		#define REGULAR_FLAGS (IOSQE_IO_DRAIN)
-	#elif defined(CFA_HAVE_IOSQE_ASYNC)
-		#define REGULAR_FLAGS (IOSQE_ASYNC)
-	#else
-		#define REGULAR_FLAGS (0)
-	#endif
-
-	#if defined(CFA_HAVE_IOSQE_IO_LINK) && defined(CFA_HAVE_IOSQE_IO_HARDLINK)
-		#define LINK_FLAGS (IOSQE_IO_LINK | IOSQE_IO_HARDLINK)
-	#elif defined(CFA_HAVE_IOSQE_IO_LINK)
-		#define LINK_FLAGS (IOSQE_IO_LINK)
-	#elif defined(CFA_HAVE_IOSQE_IO_HARDLINK)
-		#define LINK_FLAGS (IOSQE_IO_HARDLINK)
-	#else
-		#define LINK_FLAGS (0)
-	#endif
-
-	#if defined(CFA_HAVE_SPLICE_F_FD_IN_FIXED)
-		#define SPLICE_FLAGS (SPLICE_F_FD_IN_FIXED)
-	#else
-		#define SPLICE_FLAGS (0)
-	#endif
+	static const __u8 REGULAR_FLAGS = 0
+		#if defined(CFA_HAVE_IOSQE_FIXED_FILE)
+			| IOSQE_FIXED_FILE
+		#endif
+		#if defined(CFA_HAVE_IOSQE_IO_DRAIN)
+			| IOSQE_IO_DRAIN
+		#endif
+		#if defined(CFA_HAVE_IOSQE_ASYNC)
+			| IOSQE_ASYNC
+		#endif
+	;
+
+	static const __u32 LINK_FLAGS = 0
+		#if defined(CFA_HAVE_IOSQE_IO_LINK)
+			| IOSQE_IO_LINK
+		#endif
+		#if defined(CFA_HAVE_IOSQE_IO_HARDLINK)
+			| IOSQE_IO_HARDLINK
+		#endif
+	;
+
+	static const __u32 SPLICE_FLAGS = 0
+		#if defined(CFA_HAVE_SPLICE_F_FD_IN_FIXED)
+			| SPLICE_F_FD_IN_FIXED
+		#endif
+	;
 
 	extern [* struct io_uring_sqe, __u32] __submit_alloc( struct __io_data & ring, __u64 data );
Index: libcfa/src/concurrency/snzi.hfa
===================================================================
--- libcfa/src/concurrency/snzi.hfa	(revision 8fc9a5fcdfcbc515e3c551f072da9656d0800e52)
+++ libcfa/src/concurrency/snzi.hfa	(revision 290553a54a5500f937216fcdee0d5dab8d5826bc)
@@ -36,5 +36,5 @@
 static inline void depart( __snzi_node_t & );
 
-#define __snzi_half -1
+static const int __snzi_half = -1;
 
 //--------------------------------------------------