diff -up gdbm-1.9.1/src/falloc.c.zeroheaders gdbm-1.9.1/src/falloc.c
--- gdbm-1.9.1/src/falloc.c.zeroheaders	2011-08-03 21:22:23.000000000 +0200
+++ gdbm-1.9.1/src/falloc.c	2011-08-24 18:23:16.876903878 +0200
@@ -255,7 +255,7 @@ push_avail_block (GDBM_FILE dbf)
 
 
   /* Split the header block. */
-  temp = (avail_block *) malloc (av_size);
+  temp = (avail_block *) calloc (1, av_size);
   if (temp == NULL) _gdbm_fatal (dbf, "malloc error");
   /* Set the size to be correct AFTER the pop_avail_block. */
   temp->size = dbf->header->avail.size;
diff -up gdbm-1.9.1/src/gdbmopen.c.zeroheaders gdbm-1.9.1/src/gdbmopen.c
--- gdbm-1.9.1/src/gdbmopen.c.zeroheaders	2011-08-12 22:22:52.000000000 +0200
+++ gdbm-1.9.1/src/gdbmopen.c	2011-08-24 18:23:16.877903878 +0200
@@ -204,7 +204,7 @@ gdbm_open (const char *file, int block_s
 	file_block_size = block_size;
 
       /* Get space for the file header. */
-      dbf->header = (gdbm_file_header *) malloc (file_block_size);
+      dbf->header = (gdbm_file_header *) calloc (1, file_block_size);
       if (dbf->header == NULL)
 	{
 	  gdbm_close (dbf);
@@ -248,7 +248,7 @@ gdbm_open (const char *file, int block_s
 	(dbf->header->block_size - sizeof (hash_bucket))
 	/ sizeof (bucket_element) + 1;
       dbf->header->bucket_size  = dbf->header->block_size;
-      dbf->bucket = (hash_bucket *) malloc (dbf->header->bucket_size);
+      dbf->bucket = (hash_bucket *) calloc (1, dbf->header->bucket_size);
       if (dbf->bucket == NULL)
 	{
 	  gdbm_close (dbf);
@@ -440,7 +440,7 @@ _gdbm_init_cache(GDBM_FILE dbf, size_t s
       for(index = 0; index < size; index++)
         {
           (dbf->bucket_cache[index]).ca_bucket
-            = (hash_bucket *) malloc (dbf->header->bucket_size);
+            = (hash_bucket *) calloc (1, dbf->header->bucket_size);
           if ((dbf->bucket_cache[index]).ca_bucket == NULL)
 	    {
               gdbm_errno = GDBM_MALLOC_ERROR;