diff --git a/Makefile b/Makefile
index 02e9da7..4e03ab6 100644
--- a/Makefile
+++ b/Makefile
@@ -1,11 +1,9 @@
 CC := g++ -m64 -std=c++17
 OBJ_DIR := bin
-$(shell mkdir -p $(OBJ_DIR))
 SRC_DIR := .
-#CFLAGS := -Og -g -Wall -Wextra -Wno-error=unused-function -pedantic -rdynamic
-#CFLAGS := $(CFLAGS) -pg -ggdb3
-#CFLAGS := $(CFLAGS) -D__DEBUG
-CFLAGS := -O4 -Wall -Wextra -Wno-error=unused-function
+#CFLAGS := -Og -g -rdynamic -pg -ggdb3 -D__DEBUG
+CFLAGS := -O2
+CFLAGS := $(CFLAGS) -Wall -Wextra -Wno-error=unused-function -pedantic
 EXEC := $(OBJ_DIR)/data
 SRC := $(wildcard $(SRC_DIR)/*.cpp)
 HEADER := $(wildcard $(SRC_DIR)/*.hpp)
@@ -16,11 +14,14 @@ ifeq ($(OS), Windows_NT)
 endif
 OBJ := $(SRC:$(SRC_DIR)/%.cpp=$(OBJ_DIR)/%.$(OBJ_EXT))
 
-.PHONY: all start clean mrproper
+.PHONY: all start profile debug check r2 clean mrproper
 
 all: $(EXEC)
 
-$(OBJ_DIR)/%.$(OBJ_EXT): $(SRC_DIR)/%.cpp $(SRC_DIR)/%.hpp
+$(OBJ_DIR):
+	@mkdir -v $@
+
+$(OBJ_DIR)/%.$(OBJ_EXT): $(SRC_DIR)/%.cpp $(SRC_DIR)/%.hpp | $(OBJ_DIR)
 	@echo Compiling $<
 	@$(CC) $(CFLAGS) -c $< -o $@
 
@@ -31,20 +32,43 @@ $(EXEC): $(OBJ)
 start: $(EXEC)
 	@./$(EXEC)
 
-profile: start
+profile: start | check-gprof-works check-gprof2dot-works
 	@gprof $(EXEC) gmon.out | gprof2dot | dot -Tpng -o output.png
 
-debug: $(EXEC)
+debug: $(EXEC) | check-gdb-works
 	@gdb -q -tui $(EXEC) -x copies
 
-check: $(EXEC)
+check: $(EXEC) | check-valgrind-works
 	@valgrind -q -s --leak-check=full --show-leak-kinds=all $(EXEC)
 
-r2: $(EXEC)
+r2: $(EXEC) | check-r2-works
 	@r2 $(EXEC)
 
 clean:
-	@rm $(EXEC) gmon.out output.png
+	@rm -fv $(EXEC) gmon.out output.png
 
-mrproper:
-	@rm -r $(OBJ_DIR)
+mrproper: clean
+	@rm -rv $(OBJ_DIR)
+
+.PHONY: check-env
+check-env: check-gprof2dot-works check-gprof-works check-gdb-works check-valgrind-works check-r2-works
+
+.PHONY: check-gprof2dot-works
+check-gprof2dot-works:
+	@gprof2dot --help >/dev/null 2>&1 || (echo 'Please install gprof2dot.' && exit 1)
+
+.PHONY: check-gprof-works
+check-gprof-works:
+	@gprof --version >/dev/null 2>&1 || (echo 'Please install gprof.' && exit 1)
+
+.PHONY: check-gdb-works
+check-gdb-works:
+	@gdb --version >/dev/null 2>&1 || (echo 'Please install gdb.' && exit 1)
+
+.PHONY: check-valgrind-works
+check-valgrind-works:
+	@valgrind --version >/dev/null 2>&1 || (echo 'Please install valgrind.' && exit 1)
+
+.PHONY: check-r2-works
+check-r2-works:
+	@r2 -v >/dev/null 2>&1 || (echo 'Please install r2.' && exit 1)