Index: uspace/lib/libc/generic/as.c
===================================================================
--- uspace/lib/libc/generic/as.c	(revision ee369f328b8ba41006819001f0b3525418a97249)
+++ uspace/lib/libc/generic/as.c	(revision e1ab30f8f158334f3d988bcc8214bbdff1fd3cca)
@@ -31,5 +31,5 @@
  */
 /** @file
- */ 
+ */
 
 #include <as.h>
@@ -103,5 +103,5 @@
 static size_t maxheapsize = (size_t) (-1);
 
-static void * last_allocated = 0;
+static void *last_allocated = 0;
 
 /* Start of heap linker symbol */
@@ -120,13 +120,13 @@
 	
 	/* Check for invalid values */
-	if (incr < 0 && -incr > heapsize)
+	if ((incr < 0) && (((size_t) -incr) > heapsize))
 		return NULL;
 	
 	/* Check for too large value */
-	if (incr > 0 && incr+heapsize < heapsize)
+	if ((incr > 0) && (incr + heapsize < heapsize))
 		return NULL;
 	
 	/* Check for too small values */
-	if (incr < 0 && incr+heapsize > heapsize)
+	if ((incr < 0) && (incr + heapsize > heapsize))
 		return NULL;
 	
@@ -176,5 +176,5 @@
 
 	/* Set heapsize to some meaningful value */
-	if (maxheapsize == -1)
+	if (maxheapsize == (size_t) -1)
 		set_maxheapsize(MAX_HEAP_SIZE);