diff --git a/configure.ac b/configure.ac
index 45c5f623f69..342c09eee10 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1555,7 +1555,6 @@ PHP_SUBST_OLD(EXTRA_LIBS)
 PHP_SUBST_OLD(ZEND_EXTRA_LIBS)
 PHP_SUBST_OLD(INCLUDES)
 PHP_SUBST_OLD(EXTRA_INCLUDES)
-PHP_SUBST_OLD(INCLUDE_PATH)
 PHP_SUBST_OLD(INSTALL_IT)
 PHP_SUBST(LFLAGS)
 PHP_SUBST(LIBTOOL)