diff --git a/precheck/pin_check.py b/precheck/pin_check.py
index aa85fa5..b7fac07 100644
--- a/precheck/pin_check.py
+++ b/precheck/pin_check.py
@@ -112,14 +112,14 @@ def parse_dbu_to_nm(value: str, dbu_per_micron: int):
 
 
 def pin_check(
-    gds: str, lef: str, template_def: str, toplevel: str, uses_3v3: bool, tech: str
+    gds: str, lef: str, template_def: str, toplevel: str, uses_vapwr: bool, tech: str
 ):
     logging.info("Running pin check...")
     logging.info(f"* gds: {gds}")
     logging.info(f"* lef: {lef}")
     logging.info(f"* template_def: {template_def}")
     logging.info(f"* toplevel: {toplevel}")
-    logging.info(f"* uses_3v3: {uses_3v3}")
+    logging.info(f"* uses_vapwr: {uses_vapwr}")
 
     # parse pins from template def
     # def syntax: https://coriolis.lip6.fr/doc/lefdef/lefdefref/DEFSyntax.html
@@ -201,7 +201,7 @@ def pin_check(
     rect_re = re.compile(r"RECT (\S+) (\S+) (\S+) (\S+) ;")
 
     power_pins = ["VGND", "VDPWR"]
-    if uses_3v3:
+    if uses_vapwr:
         power_pins.append("VAPWR")
     compat_pins = {"VPWR": "VDPWR"}
 
diff --git a/precheck/precheck.py b/precheck/precheck.py
index 68bc1fa..5ab5444 100644
--- a/precheck/precheck.py
+++ b/precheck/precheck.py
@@ -181,9 +181,9 @@ def boundary_check(gds: str, tech: str):
         raise PrecheckFailure("Shapes outside project area")
 
 
-def power_pin_check(verilog: str, lef: str, uses_3v3: bool):
+def power_pin_check(verilog: str, lef: str, uses_vapwr: bool):
     """Ensure that VPWR / VGND are present and have USE definitions,
-    and that VAPWR is present if and only if 'uses_3v3' is set."""
+    and that VAPWR is present if and only if 'uses_vapwr' is set."""
     verilog_s = open(verilog).read().replace("VPWR", "VDPWR")
     lef_s = open(lef).read().replace("VPWR", "VDPWR")
 
@@ -198,7 +198,7 @@ def power_pin_check(verilog: str, lef: str, uses_3v3: bool):
     )
 
     for ft, s in (("Verilog", verilog_s), ("LEF", lef_s)):
-        for pwr, ex in (("VGND", True), ("VDPWR", True), ("VAPWR", uses_3v3)):
+        for pwr, ex in (("VGND", True), ("VDPWR", True), ("VAPWR", uses_vapwr)):
             if (pwr in s) and not ex:
                 raise PrecheckFailure(f"{ft} contains {pwr}")
             if not (pwr in s) and ex:
@@ -269,7 +269,12 @@ def urpm_nwell_check(gds: str, top_module: str):
 
 
 def analog_pin_check(
-    gds: str, tech: str, is_analog: bool, uses_3v3: bool, analog_pins: int, pinout: dict
+    gds: str,
+    tech: str,
+    is_analog: bool,
+    uses_vapwr: bool,
+    analog_pins: int,
+    pinout: dict,
 ):
     """Check that every analog pin connects to a piece of metal
     if and only if the pin is used according to info.yaml."""
@@ -279,7 +284,7 @@ def analog_pin_check(
         filtered = {}
 
         for pin, (rect, pin_layer, via_layers) in enumerate(
-            analog_pin_rects(tech, uses_3v3)
+            analog_pin_rects(tech, uses_vapwr)
         ):
             for layer in [pin_layer] + via_layers:
                 if layer not in filtered:
@@ -390,17 +395,19 @@ def main():
     top_module = yaml_data["project"].get("top_module", f"tt_um_wokwi_{wokwi_id}")
     assert top_module == os.path.basename(gds_stem)
 
-    tiles = yaml_data.get("project", {}).get("tiles", "1x1")
-    analog_pins = yaml_data.get("project", {}).get("analog_pins", 0)
+    project_cfg = yaml_data.get("project", {})
+    tiles = project_cfg.get("tiles", "1x1")
+    analog_pins = project_cfg.get("analog_pins", 0)
     is_analog = analog_pins > 0
-    uses_3v3 = bool(yaml_data.get("project", {}).get("uses_3v3", False))
+    # "uses_3v3" is the legacy name for "uses_vapwr"; still accepted for compat.
+    uses_vapwr = bool(project_cfg.get("uses_vapwr", project_cfg.get("uses_3v3", False)))
     pinout = yaml_data.get("pinout", {})
-    if uses_3v3 and not is_analog:
-        raise PrecheckFailure("Projects with 3v3 power need at least one analog pin")
+    if uses_vapwr and not is_analog:
+        raise PrecheckFailure("Projects with VAPWR power need at least one analog pin")
     def_root = f"../tech/{tech}/def"
     if is_analog:
         analog_def = f"{def_root}/analog/tt_analog_{tiles}"
-        if uses_3v3:
+        if uses_vapwr:
             # gf180's second supply rail is "pgvaa" (its core is already 3v3, so
             # "_3v3" is a misnomer); fall back to "_3v3" for techs that use it.
             template_def = f"{analog_def}_pgvaa.def"
@@ -465,13 +472,13 @@ def main():
         {
             "name": "Pin check",
             "check": lambda: pin_check(
-                gds_file, lef_file, template_def, top_module, uses_3v3, tech
+                gds_file, lef_file, template_def, top_module, uses_vapwr, tech
             ),
         },
         {"name": "Boundary check", "check": lambda: boundary_check(gds_file, tech)},
         {
             "name": "Power pin check",
-            "check": lambda: power_pin_check(verilog_file, lef_file, uses_3v3),
+            "check": lambda: power_pin_check(verilog_file, lef_file, uses_vapwr),
             "techs": ["sky130A", "gf180mcuD"],
         },
         {"name": "Layer check", "check": lambda: layer_check(gds_file, tech)},
@@ -489,7 +496,7 @@ def main():
         {
             "name": "Analog pin check",
             "check": lambda: analog_pin_check(
-                gds_file, tech, is_analog, uses_3v3, analog_pins, pinout
+                gds_file, tech, is_analog, uses_vapwr, analog_pins, pinout
             ),
             "techs": ["sky130A", "ihp-sg13g2", "gf180mcuD"],
         },
diff --git a/precheck/tech_data.py b/precheck/tech_data.py
index a1a177c..20540cb 100644
--- a/precheck/tech_data.py
+++ b/precheck/tech_data.py
@@ -96,12 +96,12 @@ valid_layers_gf180mcuD = [
 # fmt: on
 
 
-def analog_pin_rects(tech: str, uses_3v3: bool):
+def analog_pin_rects(tech: str, uses_vapwr: bool):
     if tech == "sky130A":
         pin_layer = (71, 20)  # met4
         via_layers = [(70, 44)]  # via3
         for pin_number in range(8):
-            if uses_3v3:
+            if uses_vapwr:
                 x1, y1 = 136.17 - 19.32 * pin_number, 0.0
             else:
                 x1, y1 = 151.81 - 19.32 * pin_number, 0.0
@@ -112,7 +112,7 @@ def analog_pin_rects(tech: str, uses_3v3: bool):
         pin_layer = (126, 0)  # TopMetal1
         via_layers = [(125, 0)]  # TopVia1
         for pin_number in range(8):
-            if uses_3v3:
+            if uses_vapwr:
                 raise NotImplementedError
             else:
                 x1, y1 = 190.165 - 24.48 * pin_number, 0.0
@@ -123,7 +123,7 @@ def analog_pin_rects(tech: str, uses_3v3: bool):
         pin_layer = (46, 0)  # Metal4
         via_layers = [(40, 0)]  # Via3
         for pin_number in range(8):
-            if uses_3v3:
+            if uses_vapwr:
                 x1, y1 = 307.90 - 43.68 * pin_number, 0.0
             else:
                 x1, y1 = 325.82 - 43.68 * pin_number, 0.0
diff --git a/precheck/test_precheck.py b/precheck/test_precheck.py
index be394e5..8a5ae0e 100644
--- a/precheck/test_precheck.py
+++ b/precheck/test_precheck.py
@@ -697,13 +697,13 @@ def test_shapes_outside_area(gds_shapes_outside_area: str):
 def test_wrong_power_pins_1(verilog_lef_wrong_power_pins: tuple[str, str]):
     verilog_file, lef_file = verilog_lef_wrong_power_pins
     with pytest.raises(precheck.PrecheckFailure, match="Verilog contains VAPWR"):
-        precheck.power_pin_check(verilog_file, lef_file, uses_3v3=False)
+        precheck.power_pin_check(verilog_file, lef_file, uses_vapwr=False)
 
 
 def test_wrong_power_pins_2(verilog_lef_wrong_power_pins: tuple[str, str]):
     verilog_file, lef_file = verilog_lef_wrong_power_pins
     with pytest.raises(precheck.PrecheckFailure, match="LEF doesn't contain VAPWR"):
-        precheck.power_pin_check(verilog_file, lef_file, uses_3v3=True)
+        precheck.power_pin_check(verilog_file, lef_file, uses_vapwr=True)
 
 
 def test_missing_use_power(verilog_lef_missing_use_power: tuple[str, str]):
@@ -712,7 +712,7 @@ def test_missing_use_power(verilog_lef_missing_use_power: tuple[str, str]):
         precheck.PrecheckFailure,
         match="VDPWR does not have a corresponding 'USE POWER ;'",
     ):
-        precheck.power_pin_check(verilog_file, lef_file, uses_3v3=False)
+        precheck.power_pin_check(verilog_file, lef_file, uses_vapwr=False)
 
 
 def test_missing_use_ground(verilog_lef_missing_use_ground: tuple[str, str]):
@@ -721,7 +721,7 @@ def test_missing_use_ground(verilog_lef_missing_use_ground: tuple[str, str]):
         precheck.PrecheckFailure,
         match="VGND does not have a corresponding 'USE GROUND ;'",
     ):
-        precheck.power_pin_check(verilog_file, lef_file, uses_3v3=False)
+        precheck.power_pin_check(verilog_file, lef_file, uses_vapwr=False)
 
 
 def test_invalid_layer(gds_invalid_layer: str):
diff --git a/project.py b/project.py
index 1f637fe..6854e21 100644
--- a/project.py
+++ b/project.py
@@ -203,7 +203,7 @@ class Project:
                 [("input", "inout"), "VGND", 1],
                 [("input", "inout"), "VDPWR", 1],
             ]
-            if self.info.uses_3v3:
+            if self.info.uses_vapwr:
                 required_ports += [
                     [("input", "inout"), "VAPWR", 1],
                 ]
@@ -653,7 +653,7 @@ class Project:
                     for i, desc in enumerate(self.info.pinout.ua)
                 ],
                 "is_analog": self.info.is_analog,
-                "uses_3v3": self.info.uses_3v3,
+                "uses_vapwr": self.info.uses_vapwr,
             }
         )
 
diff --git a/project_info.py b/project_info.py
index c886a04..1d78d53 100644
--- a/project_info.py
+++ b/project_info.py
@@ -131,10 +131,13 @@ class ProjectInfo:
         self.analog_pins: int = analog_pins
         self.is_analog: bool = self.analog_pins > 0
 
-        uses_3v3: bool = project_section.get("uses_3v3", False)
-        self.uses_3v3: bool = uses_3v3
-        if uses_3v3 and not self.is_analog:
-            errors.append("Projects with 3v3 power need at least one analog pin")
+        # "uses_3v3" is the legacy name for "uses_vapwr"; still accepted for compat.
+        uses_vapwr: bool = project_section.get(
+            "uses_vapwr", project_section.get("uses_3v3", False)
+        )
+        self.uses_vapwr: bool = uses_vapwr
+        if uses_vapwr and not self.is_analog:
+            errors.append("Projects with VAPWR power need at least one analog pin")
 
         language = project_section.get("language")
         if language is None:
diff --git a/shuttle.py b/shuttle.py
index 21df574..d341f58 100644
--- a/shuttle.py
+++ b/shuttle.py
@@ -101,7 +101,7 @@ class ShuttleConfig:
                         "width": width,
                         "height": height,
                         "analog": {i: None for i in range(project.info.analog_pins)},
-                        "pg_vaa": project.info.uses_3v3,
+                        "pg_vaa": project.info.uses_vapwr,
                     }
                     module_config["modules"].append(module_entry)
             if self.config.get("no_power_gating", False):
diff --git a/test_project_info.py b/test_project_info.py
index 58bdb64..b199948 100644
--- a/test_project_info.py
+++ b/test_project_info.py
@@ -15,7 +15,7 @@ def valid_yaml_data():
             "description": "Test Description",
             "tiles": "1x1",
             "analog_pins": 0,
-            "uses_3v3": False,
+            "uses_vapwr": False,
             "language": "Verilog",
             "top_module": "tt_um_test_project",
             "source_files": ["test.v"],
@@ -167,12 +167,12 @@ class TestProjectInfoProjectSection:
         ):
             ProjectInfo(valid_yaml_data, tile_sizes)
 
-    def test_uses_3v3_without_analog_pins(self, valid_yaml_data, tile_sizes):
-        valid_yaml_data["project"]["uses_3v3"] = True
+    def test_uses_vapwr_without_analog_pins(self, valid_yaml_data, tile_sizes):
+        valid_yaml_data["project"]["uses_vapwr"] = True
         valid_yaml_data["project"]["analog_pins"] = 0
         with pytest.raises(
             ProjectYamlError,
-            match="Projects with 3v3 power need at least one analog pin",
+            match="Projects with VAPWR power need at least one analog pin",
         ):
             ProjectInfo(valid_yaml_data, tile_sizes)
 
@@ -375,7 +375,7 @@ class TestProjectInfoValidCombinations:
 
     def test_valid_analog_project(self, valid_yaml_data, tile_sizes):
         valid_yaml_data["project"]["analog_pins"] = 2
-        valid_yaml_data["project"]["uses_3v3"] = True
+        valid_yaml_data["project"]["uses_vapwr"] = True
         # Include all required ua pins
         for i in range(6):
             valid_yaml_data["pinout"][f"ua[{i}]"] = f"analog_{i}" if i < 2 else ""
@@ -383,13 +383,24 @@ class TestProjectInfoValidCombinations:
         project_info = ProjectInfo(valid_yaml_data, tile_sizes)
         assert project_info.analog_pins == 2
         assert project_info.is_analog is True
-        assert project_info.uses_3v3 is True
+        assert project_info.uses_vapwr is True
+
+    def test_uses_vapwr_legacy_uses_3v3_alias(self, valid_yaml_data, tile_sizes):
+        # The legacy "uses_3v3" key is still accepted as an alias for uses_vapwr.
+        valid_yaml_data["project"]["analog_pins"] = 2
+        del valid_yaml_data["project"]["uses_vapwr"]
+        valid_yaml_data["project"]["uses_3v3"] = True
+        for i in range(6):
+            valid_yaml_data["pinout"][f"ua[{i}]"] = f"analog_{i}" if i < 2 else ""
+
+        project_info = ProjectInfo(valid_yaml_data, tile_sizes)
+        assert project_info.uses_vapwr is True
 
     def test_valid_digital_project(self, valid_yaml_data, tile_sizes):
         project_info = ProjectInfo(valid_yaml_data, tile_sizes)
         assert project_info.analog_pins == 0
         assert project_info.is_analog is False
-        assert project_info.uses_3v3 is False
+        assert project_info.uses_vapwr is False
 
     def test_optional_fields(self, valid_yaml_data, tile_sizes):
         # Test that optional fields work
@@ -406,11 +417,11 @@ class TestProjectInfoValidCombinations:
         project_info = ProjectInfo(valid_yaml_data, tile_sizes)
         assert project_info.analog_pins == 0
 
-    def test_default_uses_3v3(self, valid_yaml_data, tile_sizes):
-        # Test that uses_3v3 defaults to False when not specified
-        del valid_yaml_data["project"]["uses_3v3"]
+    def test_default_uses_vapwr(self, valid_yaml_data, tile_sizes):
+        # Test that uses_vapwr defaults to False when not specified
+        del valid_yaml_data["project"]["uses_vapwr"]
         project_info = ProjectInfo(valid_yaml_data, tile_sizes)
-        assert project_info.uses_3v3 is False
+        assert project_info.uses_vapwr is False
 
     def test_all_tile_sizes(self, valid_yaml_data, tile_sizes):
         # Test all valid tile sizes