diff --git a/src/osdef.sh b/src/osdef.sh
index d7d4f2a..6f9fea2 100755
--- a/src/osdef.sh
+++ b/src/osdef.sh
@@ -47,11 +47,7 @@
 #endif
 EOF
 
-# Mac uses precompiled headers, but we need real headers here.
-case `uname` in
-    Darwin)	$CC -I. -I$srcdir -E -no-cpp-precomp osdef0.c >osdef0.cc;;
-    *)		$CC -I. -I$srcdir -E osdef0.c >osdef0.cc;;
-esac
+$CC -I. -I$srcdir -E osdef0.c >osdef0.cc
 
 # insert a space in front of each line, so that a function name at the
 # start of the line is matched with "[)*, 	]\1[ 	(]"