diff --git a/config.m4 b/config.m4
index 28a20e3..6cc80a6 100644
--- a/config.m4
+++ b/config.m4
@@ -4,7 +4,7 @@
 
 APACHE_MODULE(tcl, embedded tcl interpreter, tcl_core.lo tcl_cmds.lo tcl_misc.lo, , yes)
 
-if test "$enable_tcl" = "yes"; then
+if test "$enable_tcl" != "no"; then
 	AC_CHECK_HEADERS(tcl.h inttypes.h int_types.h sys/mman.h)
 	AC_CHECK_FUNCS(asprintf mmap)