diff --git a/homeassistant/components/gc100/manifest.json b/homeassistant/components/gc100/manifest.json
index 55ea7d94682..8caa2f91204 100644
--- a/homeassistant/components/gc100/manifest.json
+++ b/homeassistant/components/gc100/manifest.json
@@ -2,7 +2,7 @@
   "domain": "gc100",
   "name": "Global Cach\u00e9 GC-100",
   "documentation": "https://www.home-assistant.io/integrations/gc100",
-  "requirements": ["python-gc100==1.0.3a"],
+  "requirements": ["python-gc100==1.0.3a0"],
   "codeowners": [],
   "iot_class": "local_polling"
 }
diff --git a/requirements_all.txt b/requirements_all.txt
index bc759d50a5b..5aafc1e7046 100644
--- a/requirements_all.txt
+++ b/requirements_all.txt
@@ -1853,7 +1853,7 @@ python-forecastio==1.4.0
 # python-gammu==3.1
 
 # homeassistant.components.gc100
-python-gc100==1.0.3a
+python-gc100==1.0.3a0
 
 # homeassistant.components.gitlab_ci
 python-gitlab==1.6.0
diff --git a/script/hassfest/__main__.py b/script/hassfest/__main__.py
index 1bec328702e..d4935196cc7 100644
--- a/script/hassfest/__main__.py
+++ b/script/hassfest/__main__.py
@@ -24,18 +24,19 @@ from . import (
 from .model import Config, Integration
 
 INTEGRATION_PLUGINS = [
-    json,
     codeowners,
     config_flow,
     dependencies,
+    dhcp,
+    json,
     manifest,
     mqtt,
+    requirements,
     services,
     ssdp,
     translations,
-    zeroconf,
-    dhcp,
     usb,
+    zeroconf,
 ]
 HASS_PLUGINS = [
     coverage,
@@ -103,9 +104,6 @@ def main():
 
     plugins = [*INTEGRATION_PLUGINS]
 
-    if config.requirements:
-        plugins.append(requirements)
-
     if config.specific_integrations:
         integrations = {}
 
@@ -122,7 +120,11 @@ def main():
         try:
             start = monotonic()
             print(f"Validating {plugin.__name__.split('.')[-1]}...", end="", flush=True)
-            if plugin is requirements and not config.specific_integrations:
+            if (
+                plugin is requirements
+                and config.requirements
+                and not config.specific_integrations
+            ):
                 print()
             plugin.validate(integrations, config)
             print(f" done in {monotonic() - start:.2f}s")
diff --git a/script/hassfest/requirements.py b/script/hassfest/requirements.py
index 5927824b21f..f72562f7f2f 100644
--- a/script/hassfest/requirements.py
+++ b/script/hassfest/requirements.py
@@ -9,6 +9,7 @@ import re
 import subprocess
 import sys
 
+from awesomeversion import AwesomeVersion, AwesomeVersionStrategy
 from stdlib_list import stdlib_list
 from tqdm import tqdm
 
@@ -61,6 +62,12 @@ def normalize_package_name(requirement: str) -> str:
 
 def validate(integrations: dict[str, Integration], config: Config):
     """Handle requirements for integrations."""
+    # Check if we are doing format-only validation.
+    if not config.requirements:
+        for integration in integrations.values():
+            validate_requirements_format(integration)
+        return
+
     ensure_cache()
 
     # check for incompatible requirements
@@ -74,8 +81,45 @@ def validate(integrations: dict[str, Integration], config: Config):
         validate_requirements(integration)
 
 
+def validate_requirements_format(integration: Integration) -> bool:
+    """Validate requirements format.
+
+    Returns if valid.
+    """
+    start_errors = len(integration.errors)
+
+    for req in integration.requirements:
+        if " " in req:
+            integration.add_error(
+                "requirements",
+                f'Requirement "{req}" contains a space',
+            )
+            continue
+
+        pkg, sep, version = req.partition("==")
+
+        if not sep and integration.core:
+            integration.add_error(
+                "requirements",
+                f'Requirement {req} need to be pinned "<pkg name>==<version>".',
+            )
+            continue
+
+        if AwesomeVersion(version).strategy == AwesomeVersionStrategy.UNKNOWN:
+            integration.add_error(
+                "requirements",
+                f"Unable to parse package version ({version}) for {pkg}.",
+            )
+            continue
+
+    return len(integration.errors) == start_errors
+
+
 def validate_requirements(integration: Integration):
     """Validate requirements."""
+    if not validate_requirements_format(integration):
+        return
+
     # Some integrations have not been fixed yet so are allowed to have violations.
     if integration.domain in IGNORE_VIOLATIONS:
         return
diff --git a/tests/hassfest/test_requirements.py b/tests/hassfest/test_requirements.py
new file mode 100644
index 00000000000..c65716d5d92
--- /dev/null
+++ b/tests/hassfest/test_requirements.py
@@ -0,0 +1,68 @@
+"""Tests for hassfest requirements."""
+from pathlib import Path
+
+import pytest
+
+from script.hassfest.model import Integration
+from script.hassfest.requirements import validate_requirements_format
+
+
+@pytest.fixture
+def integration():
+    """Fixture for hassfest integration model."""
+    integration = Integration(
+        path=Path("homeassistant/components/test"),
+        manifest={
+            "domain": "test",
+            "documentation": "https://example.com",
+            "name": "test",
+            "codeowners": ["@awesome"],
+            "requirements": [],
+        },
+    )
+    yield integration
+
+
+def test_validate_requirements_format_with_space(integration: Integration):
+    """Test validate requirement with space around separator."""
+    integration.manifest["requirements"] = ["test_package == 1"]
+    assert not validate_requirements_format(integration)
+    assert len(integration.errors) == 1
+    assert 'Requirement "test_package == 1" contains a space' in [
+        x.error for x in integration.errors
+    ]
+
+
+def test_validate_requirements_format_wrongly_pinned(integration: Integration):
+    """Test requirement with loose pin."""
+    integration.manifest["requirements"] = ["test_package>=1"]
+    assert not validate_requirements_format(integration)
+    assert len(integration.errors) == 1
+    assert 'Requirement test_package>=1 need to be pinned "<pkg name>==<version>".' in [
+        x.error for x in integration.errors
+    ]
+
+
+def test_validate_requirements_format_ignore_pin_for_custom(integration: Integration):
+    """Test requirement ignore pinning for custom."""
+    integration.manifest["requirements"] = ["test_package>=1"]
+    integration.path = Path("")
+    assert validate_requirements_format(integration)
+    assert len(integration.errors) == 0
+
+
+def test_validate_requirements_format_invalid_version(integration: Integration):
+    """Test requirement with invalid version."""
+    integration.manifest["requirements"] = ["test_package==invalid"]
+    assert not validate_requirements_format(integration)
+    assert len(integration.errors) == 1
+    assert "Unable to parse package version (invalid) for test_package." in [
+        x.error for x in integration.errors
+    ]
+
+
+def test_validate_requirements_format_successful(integration: Integration):
+    """Test requirement with successful result."""
+    integration.manifest["requirements"] = ["test_package==1.2.3"]
+    assert validate_requirements_format(integration)
+    assert len(integration.errors) == 0