diff --git a/common/logging.c b/common/logging.c
index 54b8c8960..b7f141920 100644
--- a/common/logging.c
+++ b/common/logging.c
@@ -195,7 +195,7 @@ parse_portno (const char *str, unsigned short *r_port)
 }
 
 
-static ssize_t
+static gpgrt_ssize_t
 fun_writer (void *cookie_arg, const void *buffer, size_t size)
 {
   struct fun_cookie_s *cookie = cookie_arg;
@@ -391,11 +391,11 @@ fun_writer (void *cookie_arg, const void *buffer, size_t size)
           DWORD nwritten;
 
           WriteFile ((HANDLE)cookie->fd, buffer, size, &nwritten, NULL);
-          return (ssize_t)size; /* Okay.  */
+          return (gpgrt_ssize_t)size; /* Okay.  */
         }
 #endif
       if (!writen (cookie->fd, buffer, size, cookie->is_socket))
-        return (ssize_t)size; /* Okay. */
+        return (gpgrt_ssize_t)size; /* Okay. */
     }
 
   if (!running_detached && cookie->fd != -1
@@ -415,7 +415,7 @@ fun_writer (void *cookie_arg, const void *buffer, size_t size)
       log_socket = -1;
     }
 
-  return (ssize_t)size;
+  return (gpgrt_ssize_t)size;
 }
 
 
diff --git a/dirmngr/http.c b/dirmngr/http.c
index 02854e46d..d623f7eaa 100644
--- a/dirmngr/http.c
+++ b/dirmngr/http.c
@@ -169,8 +169,9 @@ static assuan_fd_t connect_server (const char *server, unsigned short port,
                                    int *r_host_not_found);
 static gpg_error_t write_server (int sock, const char *data, size_t length);
 
-static ssize_t cookie_read (void *cookie, void *buffer, size_t size);
-static ssize_t cookie_write (void *cookie, const void *buffer, size_t size);
+static gpgrt_ssize_t cookie_read (void *cookie, void *buffer, size_t size);
+static gpgrt_ssize_t cookie_write (void *cookie,
+                                   const void *buffer, size_t size);
 static int cookie_close (void *cookie);
 
 
@@ -2415,7 +2416,7 @@ write_server (int sock, const char *data, size_t length)
 
 
 /* Read handler for estream.  */
-static ssize_t
+static gpgrt_ssize_t
 cookie_read (void *cookie, void *buffer, size_t size)
 {
   cookie_t c = cookie;
@@ -2497,11 +2498,11 @@ cookie_read (void *cookie, void *buffer, size_t size)
         c->content_length = 0;
     }
 
-  return nread;
+  return (gpgrt_ssize_t)nread;
 }
 
 /* Write handler for estream.  */
-static ssize_t
+static gpgrt_ssize_t
 cookie_write (void *cookie, const void *buffer_arg, size_t size)
 {
   const char *buffer = buffer_arg;
@@ -2550,7 +2551,7 @@ cookie_write (void *cookie, const void *buffer_arg, size_t size)
         nwritten = size;
     }
 
-  return nwritten;
+  return (gpgrt_ssize_t)nwritten;
 }
 
 
diff --git a/dirmngr/server.c b/dirmngr/server.c
index e08afd4a0..536354c2f 100644
--- a/dirmngr/server.c
+++ b/dirmngr/server.c
@@ -95,8 +95,8 @@ struct server_local_s
 
 
 /* Cookie definition for assuan data line output.  */
-static ssize_t data_line_cookie_write (void *cookie,
-                                       const void *buffer, size_t size);
+static gpgrt_ssize_t data_line_cookie_write (void *cookie,
+                                             const void *buffer, size_t size);
 static int data_line_cookie_close (void *cookie);
 static es_cookie_io_functions_t data_line_cookie_functions =
   {
@@ -210,14 +210,14 @@ data_line_write (assuan_context_t ctx, const void *buffer_arg, size_t size)
 
 /* A write handler used by es_fopencookie to write assuan data
    lines.  */
-static ssize_t
+static gpgrt_ssize_t
 data_line_cookie_write (void *cookie, const void *buffer, size_t size)
 {
   assuan_context_t ctx = cookie;
 
   if (data_line_write (ctx, buffer, size))
     return -1;
-  return (ssize_t)size;
+  return (gpgrt_ssize_t)size;
 }
 
 
diff --git a/sm/certdump.c b/sm/certdump.c
index f32a27cc5..0cc492af4 100644
--- a/sm/certdump.c
+++ b/sm/certdump.c
@@ -652,7 +652,7 @@ struct format_name_cookie
 };
 
 /* The writer function for the memory stream. */
-static ssize_t
+static gpgrt_ssize_t
 format_name_writer (void *cookie, const void *buffer, size_t size)
 {
   struct format_name_cookie *c = cookie;
@@ -696,7 +696,7 @@ format_name_writer (void *cookie, const void *buffer, size_t size)
   c->len += size;
   p[c->len] = 0; /* Terminate string. */
 
-  return (ssize_t)size;
+  return (gpgrt_ssize_t)size;
 }
 
 
diff --git a/sm/server.c b/sm/server.c
index e47861b43..f0512efac 100644
--- a/sm/server.c
+++ b/sm/server.c
@@ -55,8 +55,8 @@ struct server_local_s {
 
 
 /* Cookie definition for assuan data line output.  */
-static ssize_t data_line_cookie_write (void *cookie,
-                                       const void *buffer, size_t size);
+static gpgrt_ssize_t data_line_cookie_write (void *cookie,
+                                             const void *buffer, size_t size);
 static int data_line_cookie_close (void *cookie);
 static es_cookie_io_functions_t data_line_cookie_functions =
   {
@@ -129,7 +129,7 @@ has_option (const char *line, const char *name)
 
 /* A write handler used by es_fopencookie to write assuan data
    lines.  */
-static ssize_t
+static gpgrt_ssize_t
 data_line_cookie_write (void *cookie, const void *buffer, size_t size)
 {
   assuan_context_t ctx = cookie;
@@ -140,7 +140,7 @@ data_line_cookie_write (void *cookie, const void *buffer, size_t size)
       return -1;
     }
 
-  return size;
+  return (gpgrt_ssize_t)size;
 }
 
 static int