Gearing D/E Ratio

Hi

Gearing (D/E Ratio)= Debt/Equity

my question is what happens if a company wants to reinvest and instead of paying dividend, uses its retained earnings to reinvest in machinery in the company. What will happen to the D/E ratio? I am confused because i understand that equity will fall, since we are reducing equity, but will it not also increase since equity is (Assets-Liabilities). Does this mean the D/E ratio will remain unchanged?
?