diff --git a/common/mlcustomize/crypt-c.c b/common/mlcustomize/crypt-c.c
index e1bc740..e358018 100644
--- a/common/mlcustomize/crypt-c.c
+++ b/common/mlcustomize/crypt-c.c
@@ -47,7 +47,7 @@ virt_customize_crypt (value keyv, value saltv)
    */
   r = crypt (String_val (keyv), String_val (saltv));
   if (r == NULL)
-    caml_unix_error (errno, (char *) "crypt", Nothing);
+    unix_error (errno, (char *) "crypt", Nothing);
   rv = caml_copy_string (r);
 
   CAMLreturn (rv);
diff --git a/common/mltools/tools_utils-c.c b/common/mltools/tools_utils-c.c
index 21f7469..4ff42e5 100644
--- a/common/mltools/tools_utils-c.c
+++ b/common/mltools/tools_utils-c.c
@@ -126,10 +126,10 @@ guestfs_int_mllib_rfc3339_date_time_string (value unitv)
   size_t total = 0;
 
   if (clock_gettime (CLOCK_REALTIME, &ts) == -1)
-    caml_unix_error (errno, (char *) "clock_gettime", Val_unit);
+    unix_error (errno, (char *) "clock_gettime", Val_unit);
 
   if (localtime_r (&ts.tv_sec, &tm) == NULL)
-    caml_unix_error (errno, (char *) "localtime_r", caml_copy_int64 (ts.tv_sec));
+    unix_error (errno, (char *) "localtime_r", caml_copy_int64 (ts.tv_sec));
 
   /* Sadly strftime does not support nanoseconds, so what we do is:
    * - stringify everything before the nanoseconds
@@ -141,17 +141,17 @@ guestfs_int_mllib_rfc3339_date_time_string (value unitv)
 
   ret = strftime (buf, sizeof (buf), "%Y-%m-%dT%H:%M:%S.", &tm);
   if (ret == 0)
-    caml_unix_error (errno, (char *) "strftime", Val_unit);
+    unix_error (errno, (char *) "strftime", Val_unit);
   total += ret;
 
   ret = snprintf (buf + total, sizeof (buf) - total, "%09ld", ts.tv_nsec);
   if (ret == 0)
-    caml_unix_error (errno, (char *) "sprintf", caml_copy_int64 (ts.tv_nsec));
+    unix_error (errno, (char *) "sprintf", caml_copy_int64 (ts.tv_nsec));
   total += ret;
 
   ret = strftime (buf + total, sizeof (buf) - total, "%z", &tm);
   if (ret == 0)
-    caml_unix_error (errno, (char *) "strftime", Val_unit);
+    unix_error (errno, (char *) "strftime", Val_unit);
   total += ret;
 
   /* Move the timezone minutes one character to the right, moving the
diff --git a/common/mlutils/c_utils-c.c b/common/mlutils/c_utils-c.c
index f0e2798..54791ec 100644
--- a/common/mlutils/c_utils-c.c
+++ b/common/mlutils/c_utils-c.c
@@ -68,7 +68,7 @@ guestfs_int_mlutils_shell_unquote (value strv)
 
   ret = guestfs_int_shell_unquote (String_val (strv));
   if (ret == NULL)
-    caml_unix_error (errno, (char *) "guestfs_int_shell_unquote", Nothing);
+    unix_error (errno, (char *) "guestfs_int_shell_unquote", Nothing);
 
   retv = caml_copy_string (ret);
   free (ret);
@@ -102,7 +102,7 @@ guestfs_int_mlutils_full_path (value dirv, value namev)
 
   ret = guestfs_int_full_path (String_val (dirv), name);
   if (ret == NULL)
-    caml_unix_error (errno, (char *) "guestfs_int_full_path", dirv);
+    unix_error (errno, (char *) "guestfs_int_full_path", dirv);
   rv = caml_copy_string (ret);
   free (ret);
 
diff --git a/common/mlutils/unix_utils-c.c b/common/mlutils/unix_utils-c.c
index 919f526..b6ad832 100644
--- a/common/mlutils/unix_utils-c.c
+++ b/common/mlutils/unix_utils-c.c
@@ -149,7 +149,7 @@ guestfs_int_mllib_fnmatch (value patternv, value strv, value flagsv)
     /* XXX The fnmatch specification doesn't mention what errors can
      * be returned by fnmatch.  Assume they are errnos for now.
      */
-    caml_unix_error (errno, (char *) "fnmatch", patternv);
+    unix_error (errno, (char *) "fnmatch", patternv);
   }
 }
 
@@ -182,16 +182,16 @@ guestfs_int_mllib_fsync_file (value filenamev)
   /* Note to do fsync you have to open for write. */
   fd = open (filename, O_RDWR);
   if (fd == -1)
-    caml_unix_error (errno, (char *) "open", filenamev);
+    unix_error (errno, (char *) "open", filenamev);
 
   if (fsync (fd) == -1) {
     err = errno;
     close (fd);
-    caml_unix_error (err, (char *) "fsync", filenamev);
+    unix_error (err, (char *) "fsync", filenamev);
   }
 
   if (close (fd) == -1)
-    caml_unix_error (errno, (char *) "close", filenamev);
+    unix_error (errno, (char *) "close", filenamev);
 
   CAMLreturn (Val_unit);
 }
@@ -205,13 +205,13 @@ guestfs_int_mllib_mkdtemp (value val_pattern)
 
   pattern = strdup (String_val (val_pattern));
   if (pattern == NULL)
-    caml_unix_error (errno, (char *) "strdup", val_pattern);
+    unix_error (errno, (char *) "strdup", val_pattern);
 
   ret = mkdtemp (pattern);
   if (ret == NULL) {
     int err = errno;
     free (pattern);
-    caml_unix_error (err, (char *) "mkdtemp", val_pattern);
+    unix_error (err, (char *) "mkdtemp", val_pattern);
   }
 
   rv = caml_copy_string (ret);
@@ -229,7 +229,7 @@ guestfs_int_mllib_realpath (value pathv)
 
   r = realpath (String_val (pathv), NULL);
   if (r == NULL)
-    caml_unix_error (errno, (char *) "realpath", pathv);
+    unix_error (errno, (char *) "realpath", pathv);
 
   rv = caml_copy_string (r);
   free (r);
@@ -257,7 +257,7 @@ guestfs_int_mllib_statvfs_statvfs (value pathv)
   struct statvfs buf;
 
   if (statvfs (String_val (pathv), &buf) == -1)
-    caml_unix_error (errno, (char *) "statvfs", pathv);
+    unix_error (errno, (char *) "statvfs", pathv);
 
   f_bsize = buf.f_bsize;
   f_frsize = buf.f_frsize;
@@ -281,7 +281,7 @@ guestfs_int_mllib_statvfs_statvfs (value pathv)
                            (PULARGE_INTEGER) &free_bytes_available,
                            (PULARGE_INTEGER) &total_number_of_bytes,
                            (PULARGE_INTEGER) &total_number_of_free_bytes))
-    caml_unix_error (EIO, (char *) "statvfs: GetDiskFreeSpaceEx", pathv);
+    unix_error (EIO, (char *) "statvfs: GetDiskFreeSpaceEx", pathv);
 
   /* XXX I couldn't determine how to get block size.  MSDN has a
    * unhelpful hard-coded list here:
@@ -356,7 +356,7 @@ guestfs_int_mllib_statvfs_is_network_filesystem (value pathv)
   struct statfs buf;
 
   if (statfs (String_val (pathv), &buf) == -1)
-    caml_unix_error (errno, (char *) "statvfs", pathv);
+    unix_error (errno, (char *) "statvfs", pathv);
 
   /* Some but not all of these are defined in <linux/magic.h>. */
 #ifndef CIFS_MAGIC_NUMBER