diff --git a/configure.ac b/configure.ac
index d15d422..2be314f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -139,7 +139,7 @@ if test x$enable_debug != xyes; then
     CFLAGS="-DNDEBUG $CFLAGS"
 else
     if test x$GCC = xyes; then
-        CFLAGS="-g -pedantic -Wall $CFLAGS"
+        CFLAGS="-g -pedantic -Wall -Wextra -Wno-unused-parameter $CFLAGS"
     fi
     CFLAGS="-DDEBUG $CFLAGS"
 fi