Index: mergelog-4.5/configure.in
===================================================================
--- mergelog-4.5.orig/configure.in
+++ mergelog-4.5/configure.in
@@ -10,6 +10,7 @@ AC_PROG_INSTALL()
 
 dnl Checks for programs.
 AC_PROG_CC
+AM_PROG_CC_C_O
 
 dnl Checks for libraries.
 dnl Replace `main' with a function in -lz:
Index: mergelog-4.5/src/Makefile.am
===================================================================
--- mergelog-4.5.orig/src/Makefile.am
+++ mergelog-4.5/src/Makefile.am
@@ -1,7 +1,10 @@
 bin_PROGRAMS=mergelog zmergelog
 
-mergelog: mergelog.c
-	$(COMPILE) $(LIBS) -DVERSION=\"$(VERSION)\" -Wall mergelog.c -o $@
-
-zmergelog: mergelog.c
-	$(COMPILE) $(LIBS) -DVERSION=\"$(VERSION)\" -Wall -DUSE_ZLIB mergelog.c -o $@
+# This is a bit of a hack, but it preserves the original design of the
+# upstream Makefile.am in assuming that $VERSION will be defined in the
+# Makefile that is actually fed to make.
+AM_CPPFLAGS=-DVERSION=\"@VERSION@\"
+AM_CFLAGS=-Wall
+mergelog_SOURCES = mergelog.c
+zmergelog_SOURCES = mergelog.c
+zmergelog_CPPFLAGS = $(AM_CPPFLAGS) -DUSE_ZLIB