diff --git a/amaranth/hdl/ast.py b/amaranth/hdl/_ast.py
similarity index 100%
rename from amaranth/hdl/ast.py
rename to amaranth/hdl/_ast.py
diff --git a/amaranth/hdl/cd.py b/amaranth/hdl/_cd.py
similarity index 100%
rename from amaranth/hdl/cd.py
rename to amaranth/hdl/_cd.py
diff --git a/amaranth/hdl/dsl.py b/amaranth/hdl/_dsl.py
similarity index 100%
rename from amaranth/hdl/dsl.py
rename to amaranth/hdl/_dsl.py
diff --git a/amaranth/hdl/ir.py b/amaranth/hdl/_ir.py
similarity index 100%
rename from amaranth/hdl/ir.py
rename to amaranth/hdl/_ir.py
diff --git a/amaranth/hdl/mem.py b/amaranth/hdl/_mem.py
similarity index 100%
rename from amaranth/hdl/mem.py
rename to amaranth/hdl/_mem.py
diff --git a/amaranth/hdl/xfrm.py b/amaranth/hdl/_xfrm.py
similarity index 100%
rename from amaranth/hdl/xfrm.py
rename to amaranth/hdl/_xfrm.py