diff --git a/Makefile b/Makefile
index 9ff9e08..6d2842e 100644
--- a/Makefile
+++ b/Makefile
@@ -5,7 +5,7 @@ OUTPUT = -o ${OUTPUT_BIN}
 SOURCES = ./src/* ./cmd/shell.c
 
 build: output_dir
-	gcc -Wall ${LIBRARIES} ${SOURCES} ${OUTPUT:PROG=rshell}
+	gcc -Wall -std=gnu99 ${LIBRARIES} ${SOURCES} ${OUTPUT:PROG=rshell}
 
 debug: output_dir
 	gcc -Wall -g ${LIBRARIES} ${SOURCES} ${OUTPUT:PROG=rshell}