diff --git a/preinst-swig.in b/preinst-swig.in
index ce0361895..0f49e2e5e 100755
--- a/preinst-swig.in
+++ b/preinst-swig.in
@@ -1,7 +1,7 @@
 #!/bin/sh
 builddir=`dirname $0`
-srcdir=`cd $builddir && cd @srcdir@ && pwd`
+srcdir=`cd "$builddir" && cd '@srcdir@' && pwd`
 SWIG_LIB=$srcdir/Lib
 #SWIG_LIB=`cygpath -w $srcdir/Lib` # For native Windows version of SWIG
 export SWIG_LIB
-exec $builddir/swig $*
+exec "$builddir/swig" $*