diff --git a/configure.ac b/configure.ac
index c19ca4010..cd0fc630e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -811,8 +811,11 @@ AM_COND_IF([DEBUG],
 	CHARYBDIS_C_GCC_TRY_FLAGS([-Wsuggest-override], charybdis_cv_c_gcc_w_suggest_override)
 	CHARYBDIS_C_GCC_TRY_FLAGS([-Wmissing-noreturn], charybdis_cv_c_gcc_w_missing_noreturn)
 ], [
-	CHARYBDIS_C_GCC_TRY_FLAGS([-Wno-unknown-attributes], charybdis_cv_c_gcc_w_unknown_attributes)
 	CHARYBDIS_C_GCC_TRY_FLAGS([-Wno-unknown-pragmas], charybdis_cv_c_gcc_w_unknown_pragmas)
+	AM_COND_IF([CLANG],
+	[
+		CHARYBDIS_C_GCC_TRY_FLAGS([-Wno-unknown-attributes], charybdis_cv_c_gcc_w_unknown_attributes)
+	])
 ])
 
 dnl