diff --git a/README.md b/README.md
index 41b6ce7..2d79ae0 100644
--- a/README.md
+++ b/README.md
@@ -100,7 +100,7 @@ The following are all type-casting methods of `Env`:
 - `env.float`
 - `env.decimal`
 - `env.list` (accepts optional `subcast` and `delimiter` keyword arguments)
-- `env.dict` (accepts optional `subcast_keys` and `subcast_values` keyword arguments)
+- `env.dict` (accepts optional `subcast_keys`, `subcast_values` and `delimiter` keyword arguments)
 - `env.json`
 - `env.datetime`
 - `env.date`
diff --git a/environs/__init__.py b/environs/__init__.py
index ef13d64..0a73016 100644
--- a/environs/__init__.py
+++ b/environs/__init__.py
@@ -212,6 +212,7 @@ def _preprocess_dict(
     subcast_keys: typing.Optional[Subcast] = None,
     subcast_key: typing.Optional[Subcast] = None,  # Deprecated
     subcast_values: typing.Optional[Subcast] = None,
+    delimiter: str = ",",
     **kwargs,
 ) -> typing.Mapping:
     if isinstance(value, Mapping):
@@ -224,7 +225,7 @@ def _preprocess_dict(
 
     return {
         subcast_keys_instance.deserialize(key.strip()): subcast_values_instance.deserialize(val.strip())
-        for key, val in (item.split("=", 1) for item in value.split(",") if value)
+        for key, val in (item.split("=", 1) for item in value.split(delimiter) if value)
     }
 
 
@@ -352,7 +353,7 @@ class Env:
         ma.fields.Dict,
         "dict",
         preprocess=_preprocess_dict,
-        preprocess_kwarg_names=("subcast", "subcast_keys", "subcast_key", "subcast_values"),
+        preprocess_kwarg_names=("subcast", "subcast_keys", "subcast_key", "subcast_values", "delimiter"),
     )
     json = _field2method(ma.fields.Field, "json", preprocess=_preprocess_json)
     datetime = _field2method(ma.fields.DateTime, "datetime")
diff --git a/tests/test_environs.py b/tests/test_environs.py
index 70f3034..4b3fb7f 100644
--- a/tests/test_environs.py
+++ b/tests/test_environs.py
@@ -119,6 +119,10 @@ def test_dict(self, set_env, env):
         set_env({"DICT": "key1=1,key2=2"})
         assert env.dict("DICT") == {"key1": "1", "key2": "2"}
 
+    def test_dict_with_spaces_as_delimiter(self, set_env, env):
+        set_env({"DICT": "key1=1 key2=2"})
+        assert env.dict("DICT", delimiter=" ") == {"key1": "1", "key2": "2"}
+
     def test_dict_with_subcast_values(self, set_env, env):
         set_env({"DICT": "key1=1,key2=2"})
         assert env.dict("DICT", subcast_values=int) == {"key1": 1, "key2": 2}