diff --git a/ChangeLog b/ChangeLog
index 149cfacfbb..cd96cbf69e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sat Nov 14 16:43:24 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* hash.c (ruby_setenv): get rid of crash in Solaris 8 and 10.
+	  [ruby-core:26668]
+
 Sat Nov 14 09:16:54 2009  Marc-Andre Lafortune  <ruby-core@marc-andre.ca>
 
 	* ext/bigdecimal/bigdecimal.c (BigDecimalCmp): Fix comparisons
diff --git a/hash.c b/hash.c
index 2ae9a7dd2f..497eda918b 100644
--- a/hash.c
+++ b/hash.c
@@ -2011,7 +2011,18 @@ rb_env_path_tainted(void)
     return path_tainted;
 }
 
-#if !defined(_WIN32) && !(defined(HAVE_SETENV) && defined(HAVE_UNSETENV))
+#if defined(_WIN32) || (defined(HAVE_SETENV) && defined(HAVE_UNSETENV))
+#elif defined __sun__
+static int
+in_origenv(const char *str)
+{
+    char **env;
+    for (env = origenviron; *env; ++env) {
+	if (*env == str) return 1;
+    }
+    return 0;
+}
+#else
 static int
 envix(const char *nam)
 {
@@ -2057,6 +2068,21 @@ ruby_setenv(const char *name, const char *value)
 	setenv(name,value,1);
     else
 	unsetenv(name);
+#elif defined __sun__
+    size_t len = strlen(name);
+    char **env_ptr, *str;
+    for (env_ptr = GET_ENVIRON(environ); (str = *env_ptr) != 0; ++env_ptr) {
+	if (!strncmp(str, name, len) && str[len] == '=') {
+	    if (!in_origenv(str)) free(str);
+	    while ((env_ptr[0] = env_ptr[1]) != 0) env_ptr++;
+	    break;
+	}
+    }
+    if (value) {
+	str = malloc(len += strlen(value) + 2);
+	snprintf(str, len, "%s=%s", name, value);
+	putenv(str);
+    }
 #else  /* WIN32 */
     size_t len;
     int i=envix(name);		        /* where does it go? */