diff --git a/poetry/core/factory.py b/poetry/core/factory.py
index d248dbb74..8a64a64e3 100644
--- a/poetry/core/factory.py
+++ b/poetry/core/factory.py
@@ -27,6 +27,11 @@ class Factory(object):
     Factory class to create various elements needed by Poetry.
     """
 
+    DEPRECATED_CONSTRAINT_KEY_CURRENT_KEY_MAP = {
+        "allows_prereleases": "allow_prereleases",
+        "develop": "editable",
+    }
+
     def create_poetry(
         self, cwd=None, with_dev=True
     ):  # type: (Optional[Path]. bool) -> Poetry
@@ -182,49 +187,40 @@ def create_dependency(
             constraint = "*"
 
         if isinstance(constraint, dict):
-            optional = constraint.get("optional", False)
-            python_versions = constraint.get("python")
-            platform = constraint.get("platform")
-            markers = constraint.get("markers")
-            if "allows-prereleases" in constraint:
-                message = (
-                    'The "{}" dependency specifies '
-                    'the "allows-prereleases" property, which is deprecated. '
-                    'Use "allow-prereleases" instead.'.format(name)
-                )
-                warn(message, DeprecationWarning)
-                logger.warning(message)
-
-            allows_prereleases = constraint.get(
-                "allow-prereleases", constraint.get("allows-prereleases", False)
+            constraint_without_deprecated_keys = cls.as_constraint_with_deprecated_keys_renamed_to_current_keys(
+                dependency_name=name, constraint=constraint,
             )
+            optional = constraint_without_deprecated_keys.get("optional", False)
+            python_versions = constraint_without_deprecated_keys.get("python")
+            platform = constraint_without_deprecated_keys.get("platform")
+            markers = constraint_without_deprecated_keys.get("markers")
 
-            if "git" in constraint:
+            if "git" in constraint_without_deprecated_keys:
                 # VCS dependency
                 dependency = VCSDependency(
                     name,
                     "git",
-                    constraint["git"],
-                    branch=constraint.get("branch", None),
-                    tag=constraint.get("tag", None),
-                    rev=constraint.get("rev", None),
+                    constraint_without_deprecated_keys["git"],
+                    branch=constraint_without_deprecated_keys.get("branch", None),
+                    tag=constraint_without_deprecated_keys.get("tag", None),
+                    rev=constraint_without_deprecated_keys.get("rev", None),
                     category=category,
                     optional=optional,
-                    develop=constraint.get("develop", False),
-                    extras=constraint.get("extras", []),
+                    editable=constraint_without_deprecated_keys.get("editable", False),
+                    extras=constraint_without_deprecated_keys.get("extras", []),
                 )
-            elif "file" in constraint:
-                file_path = Path(constraint["file"])
+            elif "file" in constraint_without_deprecated_keys:
+                file_path = Path(constraint_without_deprecated_keys["file"])
 
                 dependency = FileDependency(
                     name,
                     file_path,
                     category=category,
                     base=root_dir,
-                    extras=constraint.get("extras", []),
+                    extras=constraint_without_deprecated_keys.get("extras", []),
                 )
-            elif "path" in constraint:
-                path = Path(constraint["path"])
+            elif "path" in constraint_without_deprecated_keys:
+                path = Path(constraint_without_deprecated_keys["path"])
 
                 if root_dir:
                     is_file = root_dir.joinpath(path).is_file()
@@ -238,7 +234,7 @@ def create_dependency(
                         category=category,
                         optional=optional,
                         base=root_dir,
-                        extras=constraint.get("extras", []),
+                        extras=constraint_without_deprecated_keys.get("extras", []),
                     )
                 else:
                     dependency = DirectoryDependency(
@@ -247,27 +243,31 @@ def create_dependency(
                         category=category,
                         optional=optional,
                         base=root_dir,
-                        develop=constraint.get("develop", False),
-                        extras=constraint.get("extras", []),
+                        editable=constraint_without_deprecated_keys.get(
+                            "editable", False
+                        ),
+                        extras=constraint_without_deprecated_keys.get("extras", []),
                     )
-            elif "url" in constraint:
+            elif "url" in constraint_without_deprecated_keys:
                 dependency = URLDependency(
                     name,
-                    constraint["url"],
+                    constraint_without_deprecated_keys["url"],
                     category=category,
                     optional=optional,
-                    extras=constraint.get("extras", []),
+                    extras=constraint_without_deprecated_keys.get("extras", []),
                 )
             else:
-                version = constraint["version"]
+                version = constraint_without_deprecated_keys["version"]
 
                 dependency = Dependency(
                     name,
                     version,
                     optional=optional,
                     category=category,
-                    allows_prereleases=allows_prereleases,
-                    extras=constraint.get("extras", []),
+                    allows_prereleases=constraint_without_deprecated_keys.get(
+                        "allow_prereleases", False
+                    ),
+                    extras=constraint_without_deprecated_keys.get("extras", []),
                 )
 
             if not markers:
@@ -296,7 +296,7 @@ def create_dependency(
             if not marker.is_any():
                 dependency.marker = marker
 
-            dependency.source_name = constraint.get("source")
+            dependency.source_name = constraint_without_deprecated_keys.get("source")
         else:
             dependency = Dependency(name, constraint, category=category)
 
@@ -329,12 +329,23 @@ def validate(
                     if not isinstance(constraint, dict):
                         continue
 
-                    if "allows-prereleases" in constraint:
-                        result["warnings"].append(
-                            'The "{}" dependency specifies '
-                            'the "allows-prereleases" property, which is deprecated. '
-                            'Use "allow-prereleases" instead.'.format(name)
-                        )
+                    for deprecated_key in cls.deprecated_keys():
+                        if deprecated_key in constraint:
+                            if cls.constraint_has_deprecated_key_current_key_conflict(
+                                constraint, deprecated_key
+                            ):
+                                result["errors"].append(
+                                    cls.deprecated_constraint_key_current_key_conflict_error_message(
+                                        dependency_name=name,
+                                        deprecated_key=deprecated_key,
+                                    )
+                                )
+                            else:
+                                result["warnings"].append(
+                                    cls.constraint_key_deprecation_message(
+                                        dependency_name=name, key=deprecated_key
+                                    )
+                                )
 
             # Checking for scripts with extras
             if "scripts" in config:
@@ -371,3 +382,84 @@ def locate(cls, cwd):  # type: (Path) -> Path
                     cwd
                 )
             )
+
+    @classmethod
+    def deprecated_keys(cls):
+        for key in cls.DEPRECATED_CONSTRAINT_KEY_CURRENT_KEY_MAP:
+            yield key
+
+    @classmethod
+    def as_constraint_with_deprecated_keys_renamed_to_current_keys(
+        cls, dependency_name, constraint
+    ):
+        constraint_with_renamed_keys = {}
+        for key, value in constraint.items():
+            if cls.is_deprecated_constraint_key(key):
+                cls.raise_on_deprecated_constraint_key_current_key_conflict(
+                    dependency_name, constraint, key
+                )
+                cls.warn_constraint_key_is_deprecated(dependency_name, key)
+                current_key = cls.DEPRECATED_CONSTRAINT_KEY_CURRENT_KEY_MAP[key]
+                constraint_with_renamed_keys[current_key] = value
+            else:
+                constraint_with_renamed_keys[key] = value
+        return constraint_with_renamed_keys
+
+    @classmethod
+    def raise_on_deprecated_constraint_key_current_key_conflict(
+        cls, dependency_name, constraint, deprecated_key
+    ):
+        """Raise `RuntimeError` when both a deprecated key and it's current, updated counterpart (key) are contained in constraint."""
+        if cls.constraint_has_deprecated_key_current_key_conflict(
+            constraint, deprecated_key
+        ):
+            raise RuntimeError(
+                cls.deprecated_constraint_key_current_key_conflict_error_message(
+                    dependency_name, deprecated_key,
+                )
+            )
+
+    @classmethod
+    def constraint_has_deprecated_key_current_key_conflict(
+        cls, constraint, deprecated_key
+    ):
+        current_key = cls.DEPRECATED_CONSTRAINT_KEY_CURRENT_KEY_MAP[deprecated_key]
+        return current_key in constraint
+
+    @classmethod
+    def deprecated_constraint_key_current_key_conflict_error_message(
+        cls, dependency_name, deprecated_key
+    ):
+        current_key = cls.DEPRECATED_CONSTRAINT_KEY_CURRENT_KEY_MAP[deprecated_key]
+        return (
+            'The "{dependency_name}" dependency specifies '
+            'both the "{current_key}" property and the deprecated "{deprecated_key}" property. '
+            'Please remove "{deprecated_key}" and resolve value conflicts!'.format(
+                dependency_name=dependency_name,
+                current_key=current_key,
+                deprecated_key=deprecated_key,
+            )
+        )
+
+    @classmethod
+    def is_deprecated_constraint_key(cls, key):
+        return key in cls.DEPRECATED_CONSTRAINT_KEY_CURRENT_KEY_MAP
+
+    @classmethod
+    def warn_constraint_key_is_deprecated(cls, dependency_name, key):
+        message = cls.constraint_key_deprecation_message(dependency_name, key)
+        warn(message, DeprecationWarning)
+        logging.warning(message)
+
+    @classmethod
+    def constraint_key_deprecation_message(cls, dependency_name, key):
+        current_key = cls.DEPRECATED_CONSTRAINT_KEY_CURRENT_KEY_MAP[key]
+        return (
+            'The "{dependency_name}" dependency specifies '
+            'the "{deprecated_key}" property, which is deprecated. '
+            'Use "{current_key}" instead.'.format(
+                dependency_name=dependency_name,
+                deprecated_key=key,
+                current_key=current_key,
+            )
+        )
diff --git a/poetry/core/json/schemas/poetry-schema.json b/poetry/core/json/schemas/poetry-schema.json
index 81664910f..9acd830f5 100644
--- a/poetry/core/json/schemas/poetry-schema.json
+++ b/poetry/core/json/schemas/poetry-schema.json
@@ -359,9 +359,14 @@
                         "type": "string"
                     }
                 },
+                "editable": {
+                    "type": "boolean",
+                    "description": "Whether to install the dependency in editable mode."
+                },
                 "develop": {
                     "type": "boolean",
-                    "description": "Whether to install the dependency in development mode."
+                    "description": "Whether to install the dependency in editable mode.",
+                    "deprecated": true
                 }
             }
         },
@@ -435,9 +440,14 @@
                         "type": "string"
                     }
                 },
+                "editable": {
+                    "type": "boolean",
+                    "description": "Whether to install the dependency in editable mode."
+                },
                 "develop": {
                     "type": "boolean",
-                    "description": "Whether to install the dependency in development mode."
+                    "description": "Whether to install the dependency in editable mode.",
+                    "deprecated": true
                 }
             }
         },
diff --git a/poetry/core/packages/directory_dependency.py b/poetry/core/packages/directory_dependency.py
index 0e7c920ee..e40e6b3b8 100644
--- a/poetry/core/packages/directory_dependency.py
+++ b/poetry/core/packages/directory_dependency.py
@@ -16,7 +16,7 @@ def __init__(
         category="main",  # type: str
         optional=False,  # type: bool
         base=None,  # type: Path
-        develop=False,  # type: bool
+        editable=False,  # type: bool
         extras=None,  # type: Union[List[str], Set[str]]
     ):
         self._path = path
@@ -29,7 +29,7 @@ def __init__(
             except FileNotFoundError:
                 raise ValueError("Directory {} does not exist".format(self._path))
 
-        self._develop = develop
+        self._editable = editable
         self._supports_poetry = False
 
         if not self._full_path.exists():
@@ -75,8 +75,8 @@ def base(self):
         return self._base
 
     @property
-    def develop(self):
-        return self._develop
+    def editable(self):
+        return self._editable
 
     def supports_poetry(self):
         return self._supports_poetry
@@ -91,7 +91,7 @@ def with_constraint(self, constraint):
             base=self.base,
             optional=self.is_optional(),
             category=self.category,
-            develop=self._develop,
+            editable=self._editable,
             extras=self._extras,
         )
 
diff --git a/poetry/core/packages/package.py b/poetry/core/packages/package.py
index aac39afa7..0721826ca 100644
--- a/poetry/core/packages/package.py
+++ b/poetry/core/packages/package.py
@@ -96,7 +96,7 @@ def __init__(
 
         self.root_dir = None
 
-        self.develop = True
+        self.editable = True
 
     @property
     def name(self):
@@ -319,7 +319,7 @@ def to_dependency(self):
                 category=self.category,
                 optional=self.optional,
                 base=self.root_dir,
-                develop=self.develop,
+                editable=self.editable,
                 extras=self.features,
             )
         elif self.source_type == "file":
@@ -348,7 +348,7 @@ def to_dependency(self):
                 resolved_rev=self.source_resolved_reference,
                 category=self.category,
                 optional=self.optional,
-                develop=self.develop,
+                editable=self.editable,
                 extras=self.features,
             )
         else:
@@ -405,7 +405,7 @@ def clone(self):  # type: () -> "Package"
         clone.marker = self.marker
         clone.extras = self.extras
         clone.root_dir = self.root_dir
-        clone.develop = self.develop
+        clone.editable = self.editable
 
         for dep in self.requires:
             clone.requires.append(dep)
diff --git a/poetry/core/packages/vcs_dependency.py b/poetry/core/packages/vcs_dependency.py
index 6e4248668..42565df44 100644
--- a/poetry/core/packages/vcs_dependency.py
+++ b/poetry/core/packages/vcs_dependency.py
@@ -23,7 +23,7 @@ def __init__(
         resolved_rev=None,
         category="main",
         optional=False,
-        develop=False,
+        editable=False,
         extras=None,  # type: Union[List[str], Set[str]]
     ):
         self._vcs = vcs
@@ -36,7 +36,7 @@ def __init__(
         self._branch = branch
         self._tag = tag
         self._rev = rev
-        self._develop = develop
+        self._editable = editable
 
         super(VCSDependency, self).__init__(
             name,
@@ -71,9 +71,16 @@ def tag(self):
     def rev(self):
         return self._rev
 
+    @property
+    def editable(self):  # type: () -> bool
+        return self._editable
+
     @property
     def develop(self):  # type: () -> bool
-        return self._develop
+        raise DeprecationWarning(
+            "The `develop` key is deprecated, please use `editable` instead!"
+        )
+        return self.editable
 
     @property
     def reference(self):  # type: () -> str
@@ -127,7 +134,7 @@ def with_constraint(self, constraint):
             resolved_rev=self._source_resolved_reference,
             optional=self.is_optional(),
             category=self.category,
-            develop=self._develop,
+            editable=self._editable,
             extras=self._extras,
         )
 
diff --git a/tests/fixtures/project_with_deprecated_develop_dependency/pyproject.toml b/tests/fixtures/project_with_deprecated_develop_dependency/pyproject.toml
new file mode 100644
index 000000000..fbc3a9820
--- /dev/null
+++ b/tests/fixtures/project_with_deprecated_develop_dependency/pyproject.toml
@@ -0,0 +1,9 @@
+[tool.poetry]
+name = "my-package"
+version = "1.2.3"
+description = ""
+authors = ["Awesome Hacker <awesome@hacker.io>"]
+
+[tool.poetry.dependencies]
+python = "3.9.0"
+pendulum = { git = "https://github.com/sdispater/pendulum.git", develop = false }
diff --git a/tests/fixtures/project_with_editable_and_deprecated_develop_dependency/pyproject.toml b/tests/fixtures/project_with_editable_and_deprecated_develop_dependency/pyproject.toml
new file mode 100644
index 000000000..f546cd9fe
--- /dev/null
+++ b/tests/fixtures/project_with_editable_and_deprecated_develop_dependency/pyproject.toml
@@ -0,0 +1,9 @@
+[tool.poetry]
+name = "my-package"
+version = "1.2.3"
+description = ""
+authors = ["Awesome Hacker <awesome@hacker.io>"]
+
+[tool.poetry.dependencies]
+python = "3.9.0"
+pendulum = { git = "https://github.com/sdispater/pendulum.git", editable = false, develop = false }
diff --git a/tests/fixtures/project_with_invalid_dev_deps/pyproject.toml b/tests/fixtures/project_with_invalid_dev_deps/pyproject.toml
index 1d0b5a846..0e5ff836d 100644
--- a/tests/fixtures/project_with_invalid_dev_deps/pyproject.toml
+++ b/tests/fixtures/project_with_invalid_dev_deps/pyproject.toml
@@ -10,4 +10,4 @@ license = "MIT"
 [tool.poetry.extras]
 
 [tool.poetry.dev-dependencies]
-mylib = { path = "../mylib", develop = true}
+mylib = { path = "../mylib", editable = false }
diff --git a/tests/fixtures/sample_project/pyproject.toml b/tests/fixtures/sample_project/pyproject.toml
index a26d33087..54651ae49 100644
--- a/tests/fixtures/sample_project/pyproject.toml
+++ b/tests/fixtures/sample_project/pyproject.toml
@@ -25,7 +25,7 @@ classifiers = [
 python = "~2.7 || ^3.6"
 cleo = "^0.6"
 pendulum = { git = "https://github.com/sdispater/pendulum.git", branch = "2.0" }
-tomlkit = { git = "https://github.com/sdispater/tomlkit.git", rev = "3bff550", develop = false }
+tomlkit = { git = "https://github.com/sdispater/tomlkit.git", rev = "3bff550", editable = false }
 requests = { version = "^2.18", optional = true, extras=[ "security" ] }
 pathlib2 = { version = "^2.2", python = "~2.7" }
 
diff --git a/tests/masonry/builders/fixtures/with_bad_path_dep/pyproject.toml b/tests/masonry/builders/fixtures/with_bad_path_dep/pyproject.toml
index 3c7edf13a..24a98b5f6 100644
--- a/tests/masonry/builders/fixtures/with_bad_path_dep/pyproject.toml
+++ b/tests/masonry/builders/fixtures/with_bad_path_dep/pyproject.toml
@@ -6,4 +6,4 @@ authors = ["Awesome Hacker <awesome@hacker.io>"]
 
 [tool.poetry.dependencies]
 python = "^3.6"
-bogus = { path = "../only/in/dev", develop = true }
+bogus = { path = "../only/in/dev", editable = true }
diff --git a/tests/masonry/builders/fixtures/with_bad_path_dev_dep/pyproject.toml b/tests/masonry/builders/fixtures/with_bad_path_dev_dep/pyproject.toml
index 921d93af5..f0f82fc7b 100644
--- a/tests/masonry/builders/fixtures/with_bad_path_dev_dep/pyproject.toml
+++ b/tests/masonry/builders/fixtures/with_bad_path_dev_dep/pyproject.toml
@@ -8,4 +8,4 @@ authors = ["Awesome Hacker <awesome@hacker.io>"]
 python = "^3.6"
 
 [tool.poetry.dev-dependencies]
-bogus = { path = "../only/in/dev", develop = true }
+bogus = { path = "../only/in/dev", editable = true }
diff --git a/tests/test_factory.py b/tests/test_factory.py
index 525fadb49..4eb5eb0df 100644
--- a/tests/test_factory.py
+++ b/tests/test_factory.py
@@ -2,6 +2,8 @@
 from __future__ import absolute_import
 from __future__ import unicode_literals
 
+import warnings
+
 import pytest
 
 from poetry.core.factory import Factory
@@ -49,7 +51,7 @@ def test_create_poetry():
     assert pendulum.branch == "2.0"
     assert pendulum.source == "https://github.com/sdispater/pendulum.git"
     assert pendulum.allows_prereleases()
-    assert not pendulum.develop
+    assert not pendulum.editable
 
     tomlkit = dependencies["tomlkit"]
     assert tomlkit.pretty_constraint == "rev 3bff550"
@@ -58,7 +60,7 @@ def test_create_poetry():
     assert tomlkit.rev == "3bff550"
     assert tomlkit.source == "https://github.com/sdispater/tomlkit.git"
     assert tomlkit.allows_prereleases()
-    assert not tomlkit.develop
+    assert not tomlkit.editable
 
     requests = dependencies["requests"]
     assert requests.pretty_constraint == "^2.18"
@@ -182,6 +184,37 @@ def test_validate_fails():
     assert Factory.validate(content) == {"errors": [expected], "warnings": []}
 
 
+def test_validate_strict_adds_error_when_dependency_contains_editable_and_deprecated_develop_key():
+    config = TOMLFile(
+        fixtures_dir
+        / "project_with_editable_and_deprecated_develop_dependency/pyproject.toml"
+    ).read()["tool"]["poetry"]
+    expected = (
+        'The "pendulum" dependency specifies '
+        'both the "editable" property and the deprecated "develop" property. '
+        'Please remove "develop" and resolve value conflicts!'
+    )
+    assert Factory.validate(config, strict=True) == {
+        "errors": [expected],
+        "warnings": [],
+    }
+
+
+def test_validate_strict_adds_warning_when_dependency_contains_deprecated_develop_key():
+    config = TOMLFile(
+        fixtures_dir / "project_with_deprecated_develop_dependency/pyproject.toml"
+    ).read()["tool"]["poetry"]
+    expected = (
+        'The "pendulum" dependency specifies '
+        'the "develop" property, which is deprecated. '
+        'Use "editable" instead.'
+    )
+    assert Factory.validate(config, strict=True) == {
+        "errors": [],
+        "warnings": [expected],
+    }
+
+
 def test_create_poetry_fails_on_invalid_configuration():
     with pytest.raises(RuntimeError) as e:
         Factory().create_poetry(
@@ -217,3 +250,35 @@ def test_create_poetry_fails_with_invalid_dev_dependencies_iff_with_dev_is_true(
     Factory().create_poetry(
         fixtures_dir / "project_with_invalid_dev_deps", with_dev=False
     )
+
+
+def test_create_poetry_fails_when_dependency_contains_editable_and_deprecated_develop_key():
+    with pytest.raises(RuntimeError) as e:
+        Factory().create_poetry(
+            fixtures_dir / "project_with_editable_and_deprecated_develop_dependency"
+        )
+    assert (
+        'The "pendulum" dependency specifies '
+        'both the "editable" property and the deprecated "develop" property. '
+        'Please remove "develop" and resolve value conflicts!'
+    ) == str(e.value)
+
+
+def test_create_poetry_warns_when_dependency_contains_deprecated_develop_key(caplog):
+    # All warnings are triggered inside this context manager.
+    with warnings.catch_warnings(record=True) as w:
+        warnings.simplefilter("always")
+        expected = (
+            'The "pendulum" dependency specifies '
+            'the "develop" property, which is deprecated. '
+            'Use "editable" instead.'
+        )
+        Factory().create_poetry(
+            fixtures_dir / "project_with_deprecated_develop_dependency"
+        )
+        assert len(w) == 1
+        assert issubclass(w[-1].category, DeprecationWarning)
+        assert expected == str(w[-1].message)
+        for record in caplog.records:
+            assert record.levelname == "WARNING"
+        assert expected in caplog.text