diff --git a/Makefile b/Makefile
index 0c32e25..a69b3a8 100644
--- a/Makefile
+++ b/Makefile
@@ -21,7 +21,7 @@ include sources.mk
 
 CC ?= clang
 CPPFLAGS ?= -std=c99 -I includes -D_POSIX_C_SOURCE=199309L
-CFLAGS ?= -Wall -Wextra -Werror -pipe -Wpedantic -Wconversion
+CFLAGS ?= -Wall -Wextra -Werror -pipe -Wpedantic -Wconversion -Wshadow
 CFLAGS_SHARED = $(CFLAGS) -fPIC
 LDFLAGS ?=
 TEST_LDFLAGS = -lcriterion