diff --git a/mmap.h b/mmap.h
index 0681f9b..9f743be 100644
--- a/mmap.h
+++ b/mmap.h
@@ -4,27 +4,34 @@
 
 #include <stddef.h>
 
+#include <libowfat/compiler.h>
+
 #ifdef __cplusplus
 extern "C" {
 #endif
 
 /* open file for reading, mmap whole file, close file, write length of
  * map in filesize and return pointer to map. */
+__strin(1) att_write(2)
 const char* mmap_read(const char *filename,size_t* filesize);
 
 /* like mmap_read but use openat instead of open */
+__strin(1) att_write(2)
 const char* mmap_readat(const char *filename,size_t* filesize,int dirfd);
 
 /* open file for reading, mmap whole file privately (copy on write),
  * close file, write length of map in filesize and return pointer to
  * map. */
+__strin(1) att_write(2)
 char* mmap_private(const char *filename,size_t* filesize);
 
 /* open file for writing, mmap whole file shared, close file, write
  * length of map in filesize and return pointer to map. */
+__strin(1) att_write(2)
 char* mmap_shared(const char *filename,size_t* filesize);
 
 /* unmap a mapped region */
+__strin(1)
 int mmap_unmap(const char* mapped,size_t maplen);
 
 #ifdef __cplusplus
diff --git a/mmap/mmap_read.c b/mmap/mmap_read.c
index 3724b22..2245bb6 100644
--- a/mmap/mmap_read.c
+++ b/mmap/mmap_read.c
@@ -27,15 +27,15 @@ extern const char* mmap_read(const char* filename,size_t * filesize) {
   int fd=open_read(filename);
   char *map;
   if (fd>=0) {
-    register off_t o=lseek(fd,0,SEEK_END);
+    off_t o=lseek(fd,0,SEEK_END);
     if (o==0 || (sizeof(off_t)!=sizeof(size_t) && o > (off_t)(size_t)-1)) { close(fd); return 0; }
     *filesize=(size_t)o;
     if (o>0) {
-      map=mmap(0,*filesize,PROT_READ,MAP_SHARED,fd,0);
+      map=(char*)mmap(0,*filesize,PROT_READ,MAP_SHARED,fd,0);
       if (map==(char*)-1)
 	map=0;
     } else
-      map="";
+      map=(char*)"";
     close(fd);
     return map;
   }