diff --git a/src/libsysprof-capture/sp-capture-util-private.h b/src/libsysprof-capture/sp-capture-util-private.h
index 63dd5716..f686cc9c 100644
--- a/src/libsysprof-capture/sp-capture-util-private.h
+++ b/src/libsysprof-capture/sp-capture-util-private.h
@@ -29,12 +29,12 @@
 #include <unistd.h>
 
 #ifdef __linux__
-# define _sp_getpagesize getpagesize
-# define _sp_pread       pread
-# define _sp_pwrite      pwrite
-# define _sp_write       write
-# define _sp_getpid      getpid
-# define _sp_sendfile    sendfile
+# define _sp_getpagesize()     getpagesize()
+# define _sp_pread(a,b,c,d)    pread(a,b,c,d)
+# define _sp_pwrite(a,b,c,d)   pwrite(a,b,c,d)
+# define _sp_write(a,b,c)      write(a,b,c)
+# define _sp_getpid()          getpid()
+# define _sp_sendfile(a,b,c,d) sendfile(a,b,c,d)
 #else
 size_t  _sp_getpagesize (void);
 ssize_t _sp_pread       (int     fd,
diff --git a/src/libsysprof-capture/sp-capture-util.c b/src/libsysprof-capture/sp-capture-util.c
index 52a390fd..7d586034 100644
--- a/src/libsysprof-capture/sp-capture-util.c
+++ b/src/libsysprof-capture/sp-capture-util.c
@@ -34,7 +34,7 @@ static G_LOCK_DEFINE (_sp_io_sync);
 #endif
 
 size_t
-_sp_getpagesize (void)
+(_sp_getpagesize) (void)
 {
   static size_t pgsz = 0;
 
@@ -53,10 +53,10 @@ _sp_getpagesize (void)
 }
 
 ssize_t
-_sp_pread (int     fd,
-           void   *buf,
-           size_t  count,
-           off_t   offset)
+(_sp_pread) (int     fd,
+             void   *buf,
+             size_t  count,
+             off_t   offset)
 {
 #ifdef G_OS_WIN32
   ssize_t ret = -1;
@@ -75,10 +75,10 @@ _sp_pread (int     fd,
 }
 
 ssize_t
-_sp_pwrite (int         fd,
-            const void *buf,
-            size_t      count,
-            off_t       offset)
+(_sp_pwrite) (int         fd,
+              const void *buf,
+              size_t      count,
+              off_t       offset)
 {
 #ifdef G_OS_WIN32
   ssize_t ret = -1;
@@ -97,9 +97,9 @@ _sp_pwrite (int         fd,
 }
 
 ssize_t
-_sp_write (int         fd,
-           const void *buf,
-           size_t      count)
+(_sp_write) (int         fd,
+             const void *buf,
+             size_t      count)
 {
 #ifdef G_OS_WIN32
   ssize_t ret = -1;
@@ -117,7 +117,7 @@ _sp_write (int         fd,
 }
 
 gint32
-_sp_getpid (void)
+(_sp_getpid) (void)
 {
 #ifdef G_OS_WIN32
   return _getpid ();
@@ -127,10 +127,10 @@ _sp_getpid (void)
 }
 
 ssize_t
-_sp_sendfile (int     out_fd,
-              int     in_fd,
-              off_t  *offset,
-              size_t  count)
+(_sp_sendfile) (int     out_fd,
+                int     in_fd,
+                off_t  *offset,
+                size_t  count)
 {
   ssize_t total = 0;
   off_t wpos = 0;