diff --git a/build.pri b/build.pri
index 86952bb18..ea675b6d3 100644
--- a/build.pri
+++ b/build.pri
@@ -69,3 +69,21 @@ macx-clang {
     # TODO
     WORD_SIZE = 64
 }
+
+###########################
+# No FSX for 64 bits
+###########################
+
+equals(WORD_SIZE,64): BLACK_CONFIG -= FSX
+
+################################
+# Defines for conditional compilation
+################################
+
+contains(BLACK_CONFIG, BlackSound) { DEFINES += WITH_BLACKSOUND }
+contains(BLACK_CONFIG, BlackInput) { DEFINES += WITH_BLACKINPUT }
+contains(BLACK_CONFIG, BlackSim) { DEFINES += WITH_BLACKSIM }
+contains(BLACK_CONFIG, BlackCore) { DEFINES += WITH_BLACKCORE }
+contains(BLACK_CONFIG, BlackGui) { DEFINES += WITH_BLACKGUI }
+contains(BLACK_CONFIG, FSX) { DEFINES += WITH_FSX }
+contains(BLACK_CONFIG, XPlane) { DEFINES += WITH_XPLANE }
diff --git a/client.pro b/client.pro
index c4c546c1d..3c08932c9 100644
--- a/client.pro
+++ b/client.pro
@@ -1,4 +1,5 @@
 include (config.pri)
+include (build.pri)
 
 TEMPLATE = subdirs
 CONFIG += ordered
diff --git a/config.pri b/config.pri
index f39c01056..44a8c1229 100644
--- a/config.pri
+++ b/config.pri
@@ -30,15 +30,3 @@ BLACK_CONFIG    += Unittests
 BLACK_CONFIG    += FSX
 #BLACK_CONFIG    += XPlane
 #BLACK_CONFIG    += Doxygen
-
-################################
-# Defines, for compile time code
-################################
-
-contains(BLACK_CONFIG, BlackSound) { DEFINES += WITH_BLACKSOUND }
-contains(BLACK_CONFIG, BlackInput) { DEFINES += WITH_BLACKINPUT }
-contains(BLACK_CONFIG, BlackSim) { DEFINES += WITH_BLACKSIM }
-contains(BLACK_CONFIG, BlackCore) { DEFINES += WITH_BLACKCORE }
-contains(BLACK_CONFIG, BlackGui) { DEFINES += WITH_BLACKGUI }
-contains(BLACK_CONFIG, FSX) { DEFINES += WITH_FSX }
-contains(BLACK_CONFIG, XPlane) { DEFINES += WITH_XPLANE }