-sed -i -e 's/\(#define WIMLIB_MAJOR_VERSION[[:space:]]\+\)[[:digit:]]\+/\1'$newmajor'/' \
- -e 's/\(#define WIMLIB_MINOR_VERSION[[:space:]]\+\)[[:digit:]]\+/\1'$newminor'/' \
- -e 's/\(#define WIMLIB_PATCH_VERSION[[:space:]]\+\)[[:digit:]]\+/\1'$newpatch'/' \
- -e 's/\(the library interface of wimlib \)'$oldver'/\1'$newver'/' \
+sed -i -e 's/\(#define WIMLIB_MAJOR_VERSION[[:space:]]\+\)[[:digit:]]\+/\1'"$newmajor"'/' \
+ -e 's/\(#define WIMLIB_MINOR_VERSION[[:space:]]\+\)[[:digit:]]\+/\1'"$newminor"'/' \
+ -e 's/\(#define WIMLIB_PATCH_VERSION[[:space:]]\+\)[[:digit:]]\+/\1'"$newpatch"'/' \
+ -e 's/\(the library interface of wimlib \)'"$oldver"'/\1'"$newver"'/' \