diff --git a/dirmngr/cdb.h b/dirmngr/cdb.h
--- a/dirmngr/cdb.h
+++ b/dirmngr/cdb.h
@@ -20,9 +20,6 @@
 struct cdb {
   int cdb_fd;			/* file descriptor */
   /* private members */
-#ifdef HAVE_W32_SYSTEM
-  void *cdb_mapping;            /* Mapping handle.  */
-#endif
   cdbi_t cdb_fsize;		/* datafile size */
   const unsigned char *cdb_mem; /* mmap'ed file memory */
   cdbi_t cdb_vpos, cdb_vlen;	/* found data */
diff --git a/dirmngr/cdblib.c b/dirmngr/cdblib.c
--- a/dirmngr/cdblib.c
+++ b/dirmngr/cdblib.c
@@ -115,9 +115,7 @@
 {
   struct stat st;
   unsigned char *mem;
-#ifdef _WIN32
-  HANDLE hFile, hMapping;
-#else
+#ifndef _WIN32
   unsigned int fsize;
 #endif
 
@@ -129,23 +127,26 @@
     gpg_err_set_errno (EPROTO);
     return -1;
   }
-  /* memory-map file */
 #ifdef _WIN32
-# ifdef __MINGW32CE__
-  hFile = fd;
-# else
-  hFile = (HANDLE) _get_osfhandle(fd);
-# endif
-  if (hFile == (HANDLE) -1)
-    return -1;
-  hMapping = CreateFileMapping(hFile, NULL, PAGE_READONLY, 0, 0, NULL);
-  if (!hMapping)
+  /* Read the full file */
+  mem = malloc (st.st_size);
+  if (!mem) {
+    gpg_err_set_errno (ENOMEM);
     return -1;
-  mem = (unsigned char *)MapViewOfFile(hMapping, FILE_MAP_READ, 0, 0, 0);
-  if (!mem)
+  }
+
+  /* error out if the file was somehow modified */
+  if (read (fd, mem, st.st_size) != st.st_size) {
+    free (mem);
+    gpg_err_set_errno (EIO);
     return -1;
-  cdbp->cdb_mapping = hMapping;
+  }
+
+  close (fd);
+  fd = -1;
+
 #else /*!_WIN32*/
+  /* memory-map file */
   fsize = (unsigned int)(st.st_size & 0xffffffffu);
   mem = (unsigned char*)mmap(NULL, fsize, PROT_READ, MAP_SHARED, fd, 0);
   if (mem == MAP_FAILED)
@@ -182,9 +183,7 @@
 {
   if (cdbp->cdb_mem) {
 #ifdef _WIN32
-    UnmapViewOfFile ((void*) cdbp->cdb_mem);
-    CloseHandle (cdbp->cdb_mapping);
-    cdbp->cdb_mapping = NULL;
+    free ((void*)cdbp->cdb_mem);
 #else
     munmap((void*)cdbp->cdb_mem, cdbp->cdb_fsize);
 #endif /* _WIN32 */
diff --git a/dirmngr/crlcache.c b/dirmngr/crlcache.c
--- a/dirmngr/crlcache.c
+++ b/dirmngr/crlcache.c
@@ -372,7 +372,7 @@
           int fd = cdb_fileno (entry->cdb);
           cdb_free (entry->cdb);
           xfree (entry->cdb);
-          if (close (fd))
+          if (fd != -1 && close (fd))
             log_error (_("error closing cache file: %s\n"), strerror(errno));
         }
       xfree (entry->release_ptr);