diff --git a/scripts/makefile.linux b/scripts/makefile.linux
index b23f74a..139fb05 100644
--- a/scripts/makefile.linux
+++ b/scripts/makefile.linux
@@ -6,7 +6,7 @@
 # Library name:
 LIBNAME = libpng12
 PNGMAJ = 0
-PNGMIN = 1.2.10beta6
+PNGMIN = 1.2.10beta7
 PNGVER = $(PNGMAJ).$(PNGMIN)
 
 # Shared library names:
@@ -29,7 +29,7 @@
 # libpng12/png.h and libpng12/pngconf.h
 # Prefix must be a full pathname.
 prefix=/usr/local
-exec_prefix=$prefix
+exec_prefix=$(prefix)
 
 # Where the zlib library and include files are located.
 #ZLIBLIB=/usr/local/lib