diff --git a/build.sh b/build.sh
index c8414aa..daec5ee 100755
--- a/build.sh
+++ b/build.sh
@@ -35,7 +35,7 @@ $SRC
 if [ ! -f "kerep/bin/libkerep-$OS-$ARCH.a" ]; then
     echo "libkerep-$OS-$ARCH.a not found"
     cd kerep
-    ./build.sh
+    ./build.sh "$1"
     cd ..
 fi
 
diff --git a/kerep/build.sh b/kerep/build.sh
index fe59469..f3454f9 100755
--- a/kerep/build.sh
+++ b/kerep/build.sh
@@ -2,8 +2,15 @@
 set -eo pipefail
 
 CMP="gcc"
-WARN="-std=c11 -Wall -Wno-discarded-qualifiers -Wno-unused-parameter"
-ARGS="-O2"
+WARN="-std=c99 -Wall -Wextra -Wno-discarded-qualifiers -Wno-unused-parameter"
+ARGS_DEBUG="-O0 -g"
+ARGS_RELEASE="-O2 -flto=auto -fdata-sections -ffunction-sections -Wl,--gc-sections"
+if [[ "$1" = "debug" ]]; then
+    ARGS=$ARGS_DEBUG
+else 
+    ARGS=$ARGS_RELEASE
+fi
+
 SRC="$(find src -name '*.c')"
 
 OS=$(../detect_os.sh)