diff --git a/auto/unix b/auto/unix
index ff9697a..845e41f 100644
--- a/auto/unix
+++ b/auto/unix
@@ -753,34 +753,6 @@
 fi
 
 
-if [ $ngx_found = no ]; then
-
-    # Solaris has no sys_nerr
-    ngx_feature='maximum errno'
-    ngx_feature_name=NGX_SYS_NERR
-    ngx_feature_run=value
-    ngx_feature_incs='#include <errno.h>
-                      #include <string.h>
-                      #include <stdio.h>'
-    ngx_feature_path=
-    ngx_feature_libs=
-    ngx_feature_test='int  n;
-                      char *p;
-                      for (n = 1; n < 1000; n++) {
-                          errno = 0;
-                          p = strerror(n);
-                          if (errno == EINVAL
-                              || p == NULL
-                              || strncmp(p, "Unknown error", 13) == 0)
-                          {
-                              break;
-                          }
-                      }
-                      printf("%d", n);'
-    . auto/feature
-fi
-
-
 ngx_feature="localtime_r()"
 ngx_feature_name="NGX_HAVE_LOCALTIME_R"
 ngx_feature_run=no
diff --git a/src/os/unix/ngx_errno.c b/src/os/unix/ngx_errno.c
index e787b23..b3303bf 100644
--- a/src/os/unix/ngx_errno.c
+++ b/src/os/unix/ngx_errno.c
@@ -27,6 +27,8 @@
 
 static ngx_str_t  *ngx_sys_errlist;
 static ngx_str_t   ngx_unknown_error = ngx_string("Unknown error");
+static ngx_err_t   ngx_first_error;
+static ngx_err_t   ngx_last_error;
 
 
 u_char *
@@ -34,8 +36,13 @@
 {
     ngx_str_t  *msg;
 
-    msg = ((ngx_uint_t) err < NGX_SYS_NERR) ? &ngx_sys_errlist[err]:
-                                              &ngx_unknown_error;
+    if (err >= ngx_first_error && err < ngx_last_error) {
+        msg = &ngx_sys_errlist[err - ngx_first_error];
+
+    } else {
+        msg = &ngx_unknown_error;
+    }
+
     size = ngx_min(size, msg->len);
 
     return ngx_cpymem(errstr, msg->data, size);
@@ -50,20 +57,92 @@
     size_t      len;
     ngx_err_t   err;
 
+#if (NGX_SYS_NERR)
+    ngx_first_error = 0;
+    ngx_last_error = NGX_SYS_NERR;
+
+#elif (EPERM > 1000 && EPERM < 0x7fffffff - 1000)
+
+    /*
+     * If number of errors is not known, and EPERM error code has large
+     * but reasonable value, guess possible error codes based on the error
+     * messages returned by strerror(), starting from EPERM.  Notably,
+     * this covers GNU/Hurd, where errors start at 0x40000001.
+     */
+
+    for (err = EPERM; err > EPERM - 1000; err--) {
+        ngx_set_errno(0);
+        msg = strerror(err);
+
+        if (errno == EINVAL
+            || msg == NULL
+            || strncmp(msg, "Unknown error", 13) == 0)
+        {
+            continue;
+        }
+
+        ngx_first_error = err;
+    }
+
+    for (err = EPERM; err < EPERM + 1000; err++) {
+        ngx_set_errno(0);
+        msg = strerror(err);
+
+        if (errno == EINVAL
+            || msg == NULL
+            || strncmp(msg, "Unknown error", 13) == 0)
+        {
+            continue;
+        }
+
+        ngx_last_error = err + 1;
+    }
+
+#else
+
+    /*
+     * If number of errors is not known, guess it based on the error
+     * messages returned by strerror().
+     */
+
+    ngx_first_error = 0;
+
+    for (err = 0; err < 1000; err++) {
+        ngx_set_errno(0);
+        msg = strerror(err);
+
+        if (errno == EINVAL
+            || msg == NULL
+            || strncmp(msg, "Unknown error", 13) == 0)
+        {
+            continue;
+        }
+
+        ngx_last_error = err + 1;
+    }
+
+#endif
+
     /*
      * ngx_strerror() is not ready to work at this stage, therefore,
      * malloc() is used and possible errors are logged using strerror().
      */
 
-    len = NGX_SYS_NERR * sizeof(ngx_str_t);
+    len = (ngx_last_error - ngx_first_error) * sizeof(ngx_str_t);
 
     ngx_sys_errlist = malloc(len);
     if (ngx_sys_errlist == NULL) {
         goto failed;
     }
 
-    for (err = 0; err < NGX_SYS_NERR; err++) {
+    for (err = ngx_first_error; err < ngx_last_error; err++) {
         msg = strerror(err);
+
+        if (msg == NULL) {
+            ngx_sys_errlist[err - ngx_first_error] = ngx_unknown_error;
+            continue;
+        }
+
         len = ngx_strlen(msg);
 
         p = malloc(len);
@@ -72,8 +151,8 @@
         }
 
         ngx_memcpy(p, msg, len);
-        ngx_sys_errlist[err].len = len;
-        ngx_sys_errlist[err].data = p;
+        ngx_sys_errlist[err - ngx_first_error].len = len;
+        ngx_sys_errlist[err - ngx_first_error].data = p;
     }
 
     return NGX_OK;