diff --git a/configure.in b/configure.in
index 2124e09..850136b 100644
--- a/configure.in
+++ b/configure.in
@@ -82,7 +82,7 @@ dnl ---------------------------------------------------------------------------
 AC_TYPE_SIZE_T
 TYPE_SOCKLEN_T
 
-CFLAGS="-Wall -O2 -D_REENTRANT"
+CFLAGS="$CFLAGS -Wall -D_REENTRANT"
 
 
 dnl ==============
diff --git a/libprozilla/configure.in b/libprozilla/configure.in
index 082acbe..3cbf560 100644
--- a/libprozilla/configure.in
+++ b/libprozilla/configure.in
@@ -168,7 +168,7 @@ dnl                [LIBS="$LIBS -lintl"])
   AC_SUBST(MSGFMT)
 
 
-CFLAGS="-Wall -O0 -D_REENTRANT"
+CFLAGS="$CFLAGS -Wall -D_REENTRANT"
 
 if test "x$GCC" != "xyes"; then
   enable_compiler_warnings = "no";
@@ -176,11 +176,11 @@ fi
 
 if test "x$enable_compiler_warnings" != "xno"; then
   if test "x$enable_compiler_warnings" = "xmin"; then
-    CFLAGS="$CFLAGS -g -ansi -pedantic"
+    CFLAGS="$CFLAGS -ansi -pedantic"
   fi
   if test "x$enable_compiler_warnings" = "xyes"; then
     CFLAGS="$CFLAGS \
--g -ansi -pedantic -W -Wtraditional -Wshadow -Wpointer-arith \
+-ansi -pedantic -W -Wtraditional -Wshadow -Wpointer-arith \
 -Wcast-qual -Wcast-align -Wwrite-strings -Wconversion \
 -Waggregate-return -Wstrict-prototypes -Wmissing-prototypes \
 -Wmissing-declarations -Wnested-externs -Winline"