diff --git a/config.mk b/config.mk
index 7fc045375a..f2c2c6cc94 100644
--- a/config.mk
+++ b/config.mk
@@ -194,10 +194,6 @@ BFD_ROOT_DIR =		/opt/powerpc
 endif
 endif
 
-ifeq ($(PCI_CLOCK),PCI_66M)
-CFLAGS := $(CFLAGS) -DPCI_66M
-endif
-
 #########################################################################
 
 export	HPATH HOSTCC HOSTCFLAGS CROSS_COMPILE \