diff --git a/CHANGELOG.md b/CHANGELOG.md
index 02eb2aa..6828088 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## xxx
++ **default config**: C standard changed to C99
++ **default config**: enabled more warnings
+
 ## 2.2.3
 + removed `\r` characters from `detect_os.sh`
 
diff --git a/default.config b/default.config
index 20a04dd..c3e25e7 100644
--- a/default.config
+++ b/default.config
@@ -4,10 +4,19 @@ CBUILD_VERSION=2.2.3
 PROJECT="%PROJECT_NAME%"
 CMP_C="gcc"
 CMP_CPP="g++"
-STD_C="c11"
+STD_C="c99"
 STD_CPP="c++11"
-WARN_C="-Wall -Wno-discarded-qualifiers -Wextra -Wno-unused-parameter"
-WARN_CPP="-Wall -Wextra -Wno-unused-parameter"
+WARN_C="-Wall -Wextra
+    -Wduplicated-branches
+    -Wduplicated-cond
+    -Wformat=2
+    -Wmissing-include-dirs
+    -Wshadow
+    -Werror=return-type
+    -Werror=pointer-arith
+    -Werror=init-self
+    -Werror=incompatible-pointer-types"
+WARN_CPP="$WARN_C"
 SRC_C="$(find src -name '*.c')"
 SRC_CPP="$(find src -name '*.cpp')"