diff --git a/arithmetic_progressions/Makefile b/arithmetic_progressions/Makefile
index dfa99f7..461b0f8 100644
--- a/arithmetic_progressions/Makefile
+++ b/arithmetic_progressions/Makefile
@@ -1,6 +1,6 @@
 # Rudimetary makefile
 CC=gcc
-CFLAGS= -ggdb 
+CFLAGS= -ggdb --std=c11
 
 all: ap