diff --git a/blackfin_config.mk b/blackfin_config.mk
index f71a31370ec280ef6fee8be68a0a2fc1372d99fb..beb9498e77f9bf42074198592d9731a12951e1f0 100644
--- a/blackfin_config.mk
+++ b/blackfin_config.mk
@@ -21,4 +21,5 @@
 # MA 02111-1307 USA
 #
 
-PLATFORM_CPPFLAGS += -DCONFIG_BLACKFIN -D__BLACKFIN__
+PLATFORM_RELFLAGS += -ffixed-P5
+PLATFORM_CPPFLAGS += -DCONFIG_BLACKFIN
diff --git a/cpu/bf533/config.mk b/cpu/bf533/config.mk
index 6a713c3f51faaef9d60a859ecc9eb257cc87e66f..2caa3cc7d36ae72cbe13d25fc8d9f0ba91cb2b78 100644
--- a/cpu/bf533/config.mk
+++ b/cpu/bf533/config.mk
@@ -24,4 +24,4 @@
 # MA 02110-1301 USA
 #
 
-PLATFORM_RELFLAGS += -mcpu=bf533 -ffixed-P5
+PLATFORM_RELFLAGS += -mcpu=bf533
diff --git a/cpu/bf537/config.mk b/cpu/bf537/config.mk
index 8a35789f13cc16ee619d281650c30e623d9e597d..fbbe75dede7b19908fcbaf242fa0abe7db4545ad 100644
--- a/cpu/bf537/config.mk
+++ b/cpu/bf537/config.mk
@@ -24,4 +24,4 @@
 # MA 02110-1301 USA
 #
 
-PLATFORM_RELFLAGS += -mcpu=bf537 -ffixed-P5
+PLATFORM_RELFLAGS += -mcpu=bf537
diff --git a/cpu/bf561/config.mk b/cpu/bf561/config.mk
index f4dc04bfc92452e4b027ae6e95ea11fb283d6945..3628a026b0a08d7d760f2044e0f7a1b24db9595f 100644
--- a/cpu/bf561/config.mk
+++ b/cpu/bf561/config.mk
@@ -24,4 +24,4 @@
 # MA 02110-1301 USA
 #
 
-PLATFORM_RELFLAGS += -mcpu=bf561 -ffixed-P5
+PLATFORM_RELFLAGS += -mcpu=bf561