diff --git a/src/Makefile b/src/Makefile
index 0824072d..294634f6 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -145,7 +145,7 @@ endif
 ifeq ($(COMP),gcc)
 	comp=gcc
 	CXX=g++
-	CXXFLAGS += -pedantic -Wextra -Wshadow
+	CXXFLAGS += -pedantic -Wextra -Wshadow -m$(bits)
 	ifneq ($(UNAME),Darwin)
 	   LDFLAGS += -Wl,--no-as-needed
 	endif
@@ -185,7 +185,8 @@ endif
 ifeq ($(COMP),clang)
 	comp=clang
 	CXX=clang++
-	CXXFLAGS += -pedantic -Wextra -Wshadow
+	CXXFLAGS += -pedantic -Wextra -Wshadow -m$(bits)
+	LDFLAGS += -m$(bits)
 	ifeq ($(UNAME),Darwin)
 		CXXFLAGS += -stdlib=libc++
 		DEPENDFLAGS += -stdlib=libc++