diff --git a/doc/fontconfig-user.sgml b/doc/fontconfig-user.sgml
index 43ac957..f4f1c42 100644
--- a/doc/fontconfig-user.sgml
+++ b/doc/fontconfig-user.sgml
@@ -783,6 +783,10 @@ is used to override the default configuration file.
 is used to override the default configuration directory.
   </para>
   <para>
+<emphasis>FONTCONFIG_SYSROOT</emphasis>
+is used to set a default sysroot directory.
+  </para>
+  <para>
 <emphasis>FC_DEBUG</emphasis>
 is used to output the detailed debugging messages. see <link linkend="debug">Debugging Applications</link> section for more details.
   </para>
diff --git a/src/fccfg.c b/src/fccfg.c
index e35c451..e966e57 100644
--- a/src/fccfg.c
+++ b/src/fccfg.c
@@ -2408,7 +2408,10 @@ FcConfigGetSysRoot (const FcConfig *config)
 	    return NULL;
     }
 
-    return config->sysRoot;
+    if (config->sysRoot)
+        return config->sysRoot;
+
+    return (FcChar8 *) getenv ("FONTCONFIG_SYSROOT");
 }
 
 void