diff --git a/subiquity/server/controllers/filesystem.py b/subiquity/server/controllers/filesystem.py
index 1417eceb9..ed7923ee8 100644
--- a/subiquity/server/controllers/filesystem.py
+++ b/subiquity/server/controllers/filesystem.py
@@ -1166,6 +1166,23 @@ def available_use_gap_scenarios(
                 # Do we return a reason here?
                 continue
 
+            # Now we check if we have enough room for all the primary
+            # partitions. This isn't failproof but should limit the number of
+            # UseGaps scenarios that are suggested but can't be applied because
+            # we don't have enough room for partitions.
+            new_primary_parts = 0
+            if not gap.in_extended:
+                new_primary_parts += 1  # For the rootfs to create.
+            new_primary_parts += boot.get_boot_device_plan(disk).new_partition_count()
+            # In theory, there could be a recovery partition as well. Not sure
+            # how to account for it since we don't know yet if one will be
+            # requested.
+            if new_primary_parts > gaps.remaining_primary_partitions(
+                disk, disk.alignment_data()
+            ):
+                log.error("skipping UseGap: not enough room for primary partitions")
+                continue
+
             capability_info = CapabilityInfo()
             for variation in self._variation_info.values():
                 if variation.is_core_boot_classic():
diff --git a/subiquity/server/controllers/tests/test_filesystem.py b/subiquity/server/controllers/tests/test_filesystem.py
index 15654f30f..4ca8e816a 100644
--- a/subiquity/server/controllers/tests/test_filesystem.py
+++ b/subiquity/server/controllers/tests/test_filesystem.py
@@ -24,7 +24,7 @@
 from curtin.commands.extract import TrivialSourceHandler
 from jsonschema.validators import validator_for
 
-from subiquity.common.filesystem import gaps, labels
+from subiquity.common.filesystem import boot, gaps, labels
 from subiquity.common.filesystem.actions import DeviceAction
 from subiquity.common.types.storage import (
     AddPartitionV2,
@@ -1419,17 +1419,65 @@ async def test_in_use_reformat_and_gap(self, bootloader, ptable):
             GuidedStorageTargetReformat(
                 disk_id=self.disk.id, allowed=default_capabilities
             ),
-            GuidedStorageTargetUseGap(
-                disk_id=self.disk.id,
-                allowed=default_capabilities,
-                gap=labels.for_client(gaps.largest_gap(self.disk)),
-            ),
             GuidedStorageTargetManual(),
         ]
+        # VTOC does not have enough room for an ESP + 3 partitions, presumably.
+        if ptable != "vtoc" or bootloader == Bootloader.NONE:
+            expected.insert(
+                1,
+                GuidedStorageTargetUseGap(
+                    disk_id=self.disk.id,
+                    allowed=default_capabilities,
+                    gap=labels.for_client(gaps.largest_gap(self.disk)),
+                ),
+            )
         resp = await self.fsc.v2_guided_GET()
         self.assertEqual(expected, resp.targets)
         self.assertEqual(ProbeStatus.DONE, resp.status)
 
+    @parameterized.expand(
+        (
+            (1, 4, True, True),
+            (1, 4, False, True),
+            (4, 4, True, False),
+            (4, 4, False, False),
+            (3, 4, False, True),
+            (3, 4, True, False),
+            (127, 128, True, False),
+            (127, 128, False, True),
+        )
+    )
+    async def test_available_use_gap_scenarios(
+        self,
+        existing_primaries: int,
+        max_primaries: int,
+        create_boot_part: bool,
+        expected_scenario: bool,
+    ):
+        await self._setup(Bootloader.NONE, "gpt", fix_bios=True)
+        install_min = self.fsc.calculate_suggested_install_min()
+
+        for _ in range(existing_primaries):
+            make_partition(self.model, self.disk, preserve=True, size=4 << 20)
+
+        p_max_primaries = mock.patch.object(
+            self.fsc.model._partition_alignment_data["gpt"],
+            "primary_part_limit",
+            max_primaries,
+        )
+        if create_boot_part:
+            boot_plan = boot.CreatePartPlan(mock.Mock(), mock.Mock(), mock.Mock())
+        else:
+            boot_plan = boot.NoOpBootPlan()
+        p_boot_plan = mock.patch(
+            "subiquity.server.controllers.filesystem.boot.get_boot_device_plan",
+            return_value=boot_plan,
+        )
+        with p_max_primaries, p_boot_plan:
+            scenarios = self.fsc.available_use_gap_scenarios(install_min)
+
+        self.assertEqual(expected_scenario, scenarios != [])
+
 
 class TestManualBoot(IsolatedAsyncioTestCase):
     def _setup(self, bootloader, ptable, **kw):