diff -wpruN '--exclude=*.orig' a~/Makefile a/Makefile
--- a~/Makefile	1970-01-01 00:00:00
+++ a/Makefile	1970-01-01 00:00:00
@@ -31,7 +31,7 @@ else
 DLSUFFIX = .so
 endif
 
-PG_CPPFLAGS += -D _MYSQL_LIBNAME=\"lib$(MYSQL_LIB)$(DLSUFFIX)\"
+PG_CPPFLAGS += -D _MYSQL_LIBNAME=\"$(MYSQL_LIBNAME)\"
 
 ifdef USE_PGXS
 PG_CONFIG = pg_config