diff --git a/Makefile.fpc b/Makefile.fpc
index 0db79d9462..56f3277b62 100644
--- a/Makefile.fpc
+++ b/Makefile.fpc
@@ -81,7 +81,7 @@ endif
 
 # Test dir if none specified
 ifndef PREFIXINSTALLDIR
-ifdef inlinux
+ifdef UNIXINSTALLDIR
 PREFIXINSTALLDIR=/tmp/pptest
 else
 PREFIXINSTALLDIR=/pptest