diff --git a/src/tests/add-ons/kernel/file_systems/fs_shell/cache.c b/src/tests/add-ons/kernel/file_systems/fs_shell/cache.c
index a4d4fc3597..f2d2719561 100644
--- a/src/tests/add-ons/kernel/file_systems/fs_shell/cache.c
+++ b/src/tests/add-ons/kernel/file_systems/fs_shell/cache.c
@@ -1739,7 +1739,7 @@ cache_block_io(int dev, fs_off_t bnum, void *data, fs_off_t num_blocks, int bsiz
 {
     size_t          err = 0;
     cache_ent      *ce;
-    cache_ent_list *cel;
+    cache_ent_list *cel = NULL;
 
     if (chatty_io > 1)
         printf("cbio: bnum = %Ld, num_blocks = %Ld, bsize = %d, op = %s\n", bnum, num_blocks,
@@ -1772,7 +1772,9 @@ cache_block_io(int dev, fs_off_t bnum, void *data, fs_off_t num_blocks, int bsiz
                dev, bnum, num_blocks, max_device_blocks[dev]);
 
 		// let the app crash here
-		*(int *)0x3100 = 0xc0debabe;
+		debugger("Accessed blocks out of device range!");
+		//*(int *)0x3100 = 0xc0debabe;
+
         return EINVAL;
     }
 
@@ -1787,7 +1789,6 @@ cache_block_io(int dev, fs_off_t bnum, void *data, fs_off_t num_blocks, int bsiz
             panic("*** asked to do a large locked io that's too hard!\n");
         }
 
-
         if (op & CACHE_READ) {
             if (read_phys_blocks(dev, bnum, data, num_blocks, bsize) != 0) {
                 printf("cache read:read_phys_blocks failed (%s on blocks %Ld:%Ld)!\n",
diff --git a/src/tests/add-ons/kernel/file_systems/fs_shell/rootfs.c b/src/tests/add-ons/kernel/file_systems/fs_shell/rootfs.c
index 6741d079b2..b04bdff106 100644
--- a/src/tests/add-ons/kernel/file_systems/fs_shell/rootfs.c
+++ b/src/tests/add-ons/kernel/file_systems/fs_shell/rootfs.c
@@ -656,7 +656,7 @@ rootfs_readdir(void *_ns, void *_node, void *_cookie, long *num,
     long                 i;
     vnode               *vn;
     vnode_id             vnid;
-    char                *name, *last;
+    char                *name, *last = "";
     int                  sl, rl;
 
     ns = (nspace *) _ns;
diff --git a/src/tests/add-ons/kernel/file_systems/fs_shell/sl.c b/src/tests/add-ons/kernel/file_systems/fs_shell/sl.c
index 8713bab936..8e6af4656a 100644
--- a/src/tests/add-ons/kernel/file_systems/fs_shell/sl.c
+++ b/src/tests/add-ons/kernel/file_systems/fs_shell/sl.c
@@ -159,7 +159,7 @@ int InsertSL(SkipList l, void *key)
 {
   register int i,k;
   SLNode update[MaxNumberOfLevels];
-  register SLNode p,q;
+  register SLNode p,q = 0;
   int (*compare)() = l->compare;
 
   p = l->header;
@@ -262,7 +262,7 @@ int DeleteSL(SkipList l, void *key)
 void *SearchSL(SkipList l, void *key)
 {
   register int k;
-  register SLNode p,q;
+  register SLNode p,q = 0;
   int (*compare)() = l->compare;
 
   p = l->header;