diff --git a/configure.ac b/configure.ac
index d1c5047a..5a8dd7c9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -38,10 +38,11 @@ AC_FUNC_REALLOC
 AC_CHECK_FUNCS([dup2 gettimeofday memset mkdir socket strerror])
 
 # Fix chars to unsigned
-CXXFLAGS="$CXXFLAGS -funsigned-char"
+AC_SUBST([global_CFLAGS], [-funsigned-char])
 
 #allow verbose mode compiles
-AC_ARG_ENABLE([verbose], AC_HELP_STRING([--enable-verbose], [Compile with verbose messages]), CXXFLAGS="-DDEBUG=4 $CXXFLAGS")
+AC_ARG_ENABLE([verbose], AC_HELP_STRING([--enable-verbose], [Compile with verbose messages]),
+	AC_DEFINE([DEBUG], [4]))
 
 AC_CONFIG_FILES([Makefile lib/Makefile lib/mist-1.0.pc])
 AC_OUTPUT
diff --git a/lib/Makefile.am b/lib/Makefile.am
index 55364d05..d9e8c4e5 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -1,3 +1,5 @@
+AM_CPPFLAGS = $(global_CFLAGS)
+
 lib_LTLIBRARIES=libmist-1.0.la
 libmist_1_0_la_SOURCES=amf.h amf.cpp auth.h auth.cpp base64.h base64.cpp config.h config.cpp crypto.h crypto.cpp dtsc.h dtsc.cpp flv_tag.h flv_tag.cpp http_parser.h http_parser.cpp json.h json.cpp procs.h procs.cpp rtmpchunks.h rtmpchunks.cpp socket.h socket.cpp mp4.h mp4.cpp stream.h stream.cpp
 libmist_1_0_la_LIBADD=-lssl -lcrypto