diff --git a/grayskull/config.py b/grayskull/config.py
index a4bc9a562..0961c75dc 100644
--- a/grayskull/config.py
+++ b/grayskull/config.py
@@ -74,6 +74,8 @@ def get_py_version_available(
         else:
             py_ver_enabled = {py_ver: True for py_ver in sup_python_ver}
         for op, major, minor in req_python:
+            if op == "=":
+                op = "=="
             if not minor:
                 minor = 0
             for sup_py, is_enabled in py_ver_enabled.items():
diff --git a/grayskull/strategy/py_base.py b/grayskull/strategy/py_base.py
index 6926af94e..ed069c267 100644
--- a/grayskull/strategy/py_base.py
+++ b/grayskull/strategy/py_base.py
@@ -293,8 +293,8 @@ def get_setup_cfg(source_path: str) -> dict:
     setup_cfg = read_configuration(str(path_setup_cfg))
     setup_cfg = dict(setup_cfg)
     if setup_cfg.get("options", {}).get("python_requires"):
-        setup_cfg["options"]["python_requires"] = str(
-            setup_cfg["options"]["python_requires"]
+        setup_cfg["options"]["python_requires"] = ensure_pep440(
+            str(setup_cfg["options"]["python_requires"])
         )
     result = {}
     result.update(setup_cfg.get("options", {}))
@@ -677,3 +677,30 @@ def get_sdist_metadata(
         metadata["source"] = {"url": sdist_url, "sha256": sha256_checksum(path_pkg)}
 
     return metadata
+
+
+def ensure_pep440_in_req_list(list_req: List[str]) -> List[str]:
+    return [ensure_pep440(pkg) for pkg in list_req]
+
+
+def ensure_pep440(pkg: str) -> str:
+    if not pkg:
+        return pkg
+    if pkg.strip().startswith("<{") or pkg.strip().startswith("{{"):
+        return pkg
+    split_pkg = pkg.strip().split(" ")
+    if len(split_pkg) <= 1:
+        return pkg
+    constrain_pkg = "".join(split_pkg[1:])
+    list_constrains = constrain_pkg.split(",")
+    full_constrain = []
+    for constrain in list_constrains:
+        if "~=" in constrain:
+            version = constrain.strip().replace("~=", "").strip()
+            version_reduced = ".".join(version.split(".")[:-1])
+            version_reduced += ".*"
+            full_constrain.append(f">={version},=={version_reduced}")
+        else:
+            full_constrain.append(constrain.strip())
+    all_constrains = ",".join(full_constrain)
+    return f"{split_pkg[0]} {all_constrains}"
diff --git a/grayskull/strategy/pypi.py b/grayskull/strategy/pypi.py
index 2e374f31e..2a8027656 100644
--- a/grayskull/strategy/pypi.py
+++ b/grayskull/strategy/pypi.py
@@ -21,6 +21,8 @@
     RE_DEPS_NAME,
     clean_deps_for_conda_forge,
     discover_license,
+    ensure_pep440,
+    ensure_pep440_in_req_list,
     get_compilers,
     get_entry_points_from_sdist,
     get_extra_from_requires_dist,
@@ -85,8 +87,10 @@ def get_val(key):
         "entry_points": get_entry_points_from_sdist(sdist_metadata),
         "scripts": get_val("scripts"),
         "summary": get_val("summary"),
-        "requires_python": pypi_metadata.get("requires_python")
-        or sdist_metadata.get("python_requires"),
+        "requires_python": ensure_pep440(
+            pypi_metadata.get("requires_python")
+            or sdist_metadata.get("python_requires")
+        ),
         "doc_url": get_val("doc_url"),
         "dev_url": get_val("dev_url"),
         "license": get_val("license"),
@@ -341,14 +345,17 @@ def get_metadata(recipe, config) -> dict:
     print_msg(f"License file: {Fore.LIGHTMAGENTA_EX}{license_file}")
 
     all_requirements = extract_requirements(metadata, config, recipe)
+
     if all_requirements.get("host"):
         all_requirements["host"] = solve_list_pkg_name(
             all_requirements["host"], PYPI_CONFIG
         )
+        all_requirements["host"] = ensure_pep440_in_req_list(all_requirements["host"])
     if all_requirements.get("run"):
         all_requirements["run"] = solve_list_pkg_name(
             all_requirements["run"], PYPI_CONFIG
         )
+        all_requirements["run"] = ensure_pep440_in_req_list(all_requirements["run"])
     if config.is_strict_cf:
         all_requirements["host"] = clean_deps_for_conda_forge(
             all_requirements["host"], config.py_cf_supported[0]
diff --git a/tests/test_pypi.py b/tests/test_pypi.py
index 48839cab8..d7004f3c6 100644
--- a/tests/test_pypi.py
+++ b/tests/test_pypi.py
@@ -15,6 +15,7 @@
 from grayskull.config import Configuration
 from grayskull.strategy.py_base import (
     clean_deps_for_conda_forge,
+    ensure_pep440,
     generic_py_ver_to,
     get_compilers,
     get_entry_points_from_sdist,
@@ -839,3 +840,17 @@ def test_get_test_imports_clean_modules():
         )
         == ["_pytest", "_pytest._code"]
     )
+
+
+def test_ensure_pep440():
+    assert ensure_pep440("pytest ~=5.3.2") == "pytest >=5.3.2,==5.3.*"
+
+
+def test_pep440_recipe():
+    recipe = create_python_recipe("codalab=0.5.26", is_strict_cf=False)[0]
+    assert recipe["requirements"]["host"] == ["pip", "python >=3.6,<3.7"]
+
+
+def test_pep440_in_recipe_pypi():
+    recipe = create_python_recipe("kedro=0.17.6", is_strict_cf=False)[0]
+    assert sorted(recipe["requirements"]["run"])[0] == "anyconfig >=0.10.0,==0.10.*"