-wx_major_version_number := $(shell cat configure.in | sed -n 's/^wx_major_version_number=//p')
-wx_minor_version_number := $(shell cat configure.in | sed -n 's/^wx_minor_version_number=//p')
-wx_release_number := $(shell cat configure.in | sed -n 's/^wx_release_number=//p')
-wx_subrelease_number := $(shell cat configure.in | sed -n 's/^wx_subrelease_number=//p')
+wx_major_version_number := $(shell sed -n 's/^wx_major_version_number=//p' configure.in)
+wx_minor_version_number := $(shell sed -n 's/^wx_minor_version_number=//p' configure.in)
+wx_release_number := $(shell sed -n 's/^wx_release_number=//p' configure.in)
+wx_subrelease_number := $(shell sed -n 's/^wx_subrelease_number=//p' configure.in)