Index: uspace/lib/c/generic/fibril.c
===================================================================
--- uspace/lib/c/generic/fibril.c	(revision b4df8db46336b1d3a612064e87644b1698115b9c)
+++ uspace/lib/c/generic/fibril.c	(revision db71e2af5cdfe169de296e6f39b3e5eda7a966f6)
@@ -256,5 +256,5 @@
  * @param func Implementing function of the new fibril.
  * @param arg Argument to pass to func.
- * @param stksz Stack size, -1 for the system default stack size.
+ * @param stksz Stack size in bytes.
  *
  * @return 0 on failure or TLS of the new fibril.
@@ -269,5 +269,6 @@
 		return 0;
 	
-	size_t stack_size = (stksz == (size_t) -1) ? stack_size_get() : stksz;
+	size_t stack_size = (stksz == FIBRIL_DFLT_STK_SIZE) ?
+	    stack_size_get() : stksz;
 	fibril->stack = as_area_create((void *) -1, stack_size,
 	    AS_AREA_READ | AS_AREA_WRITE | AS_AREA_CACHEABLE | AS_AREA_GUARD |