Index: uspace/srv/fs/fat/fat_fat.c
===================================================================
--- uspace/srv/fs/fat/fat_fat.c	(revision d965dc36bbda8ae669424c66f72689f935c5444f)
+++ uspace/srv/fs/fat/fat_fat.c	(revision 5b56dc7b022390dabd9e63439e7b60a3073284ae)
@@ -128,5 +128,5 @@
 {
 	fat_cluster_t firstc = nodep->firstc;
-	fat_cluster_t currc;
+	fat_cluster_t currc = 0;
 	aoff64_t relbn = bn;
 	int rc;
@@ -194,5 +194,5 @@
 	uint32_t clusters;
 	uint32_t max_clusters;
-	fat_cluster_t c;
+	fat_cluster_t c = 0;
 	int rc;
 
@@ -679,5 +679,7 @@
 	fat_cluster_t *lifo;    /* stack for storing free cluster numbers */
 	unsigned found = 0;     /* top of the free cluster number stack */
-	fat_cluster_t clst, value, clst_last1 = FAT_CLST_LAST1(bs);
+	fat_cluster_t clst;
+	fat_cluster_t value = 0;
+	fat_cluster_t clst_last1 = FAT_CLST_LAST1(bs);
 	int rc = EOK;
 
@@ -907,5 +909,6 @@
 int fat_sanity_check(fat_bs_t *bs, service_id_t service_id)
 {
-	fat_cluster_t e0, e1;
+	fat_cluster_t e0 = 0;
+	fat_cluster_t e1 = 0;
 	unsigned fat_no;
 	int rc;
Index: uspace/srv/fs/mfs/mfs_ops.c
===================================================================
--- uspace/srv/fs/mfs/mfs_ops.c	(revision d965dc36bbda8ae669424c66f72689f935c5444f)
+++ uspace/srv/fs/mfs/mfs_ops.c	(revision 5b56dc7b022390dabd9e63439e7b60a3073284ae)
@@ -773,5 +773,5 @@
 {
 	int rc;
-	fs_node_t *fn;
+	fs_node_t *fn = NULL;
 
 	rc = mfs_node_get(&fn, service_id, index);
@@ -1108,5 +1108,5 @@
 mfs_sync(service_id_t service_id, fs_index_t index)
 {
-	fs_node_t *fn;
+	fs_node_t *fn = NULL;
 	int rc = mfs_node_get(&fn, service_id, index);
 	if (rc != EOK)