diff --git a/core/dbt/adapters/base/impl.py b/core/dbt/adapters/base/impl.py
index e575a9d82e0..7c1cc592530 100644
--- a/core/dbt/adapters/base/impl.py
+++ b/core/dbt/adapters/base/impl.py
@@ -260,6 +260,10 @@ def load_macro_manifest(self) -> Manifest:
             self._macro_manifest_lazy = manifest
         return self._macro_manifest_lazy
 
+    def clear_macro_manifest(self):
+        if self._macro_manifest_lazy is not None:
+            self._macro_manifest_lazy = None
+
     ###
     # Caching methods
     ###
diff --git a/core/dbt/config/runtime.py b/core/dbt/config/runtime.py
index e11471c9830..184e2732762 100644
--- a/core/dbt/config/runtime.py
+++ b/core/dbt/config/runtime.py
@@ -355,6 +355,9 @@ def load_dependencies(self) -> Mapping[str, 'RuntimeConfig']:
             self.dependencies = all_projects
         return self.dependencies
 
+    def clear_dependencies(self):
+        self.dependencies = None
+
     def load_projects(
         self, paths: Iterable[Path]
     ) -> Iterator[Tuple[str, 'RuntimeConfig']]:
diff --git a/core/dbt/parser/manifest.py b/core/dbt/parser/manifest.py
index a580f6dd3d0..41f67bd637a 100644
--- a/core/dbt/parser/manifest.py
+++ b/core/dbt/parser/manifest.py
@@ -195,6 +195,8 @@ def load(self, macro_manifest: Manifest):
         old_results = self.read_parse_results()
         if old_results is not None:
             logger.debug('Got an acceptable cached parse result')
+
+
         self.results.macros.update(macro_manifest.macros)
         self.results.files.update(macro_manifest.files)
 
diff --git a/core/dbt/perf_utils.py b/core/dbt/perf_utils.py
index 4e8f74033f4..782859a88a3 100644
--- a/core/dbt/perf_utils.py
+++ b/core/dbt/perf_utils.py
@@ -7,7 +7,11 @@
 from dbt.config import RuntimeConfig
 
 
-def get_full_manifest(config: RuntimeConfig) -> Manifest:
+def get_full_manifest(
+    config: RuntimeConfig,
+    *,
+    reset: bool = False,
+) -> Manifest:
     """Load the full manifest, using the adapter's internal manifest if it
     exists to skip parsing internal (dbt + plugins) macros a second time.
 
@@ -15,6 +19,10 @@ def get_full_manifest(config: RuntimeConfig) -> Manifest:
     attached to the adapter for any methods that need it.
     """
     adapter = get_adapter(config)  # type: ignore
+    if reset:
+        config.clear_dependencies()
+        adapter.clear_macro_manifest()
+
     internal: Manifest = adapter.load_macro_manifest()
 
     return load_manifest(
diff --git a/core/dbt/rpc/task_manager.py b/core/dbt/rpc/task_manager.py
index 83ab7c0eabc..1ab24c395f5 100644
--- a/core/dbt/rpc/task_manager.py
+++ b/core/dbt/rpc/task_manager.py
@@ -8,6 +8,7 @@
 
 import dbt.exceptions
 import dbt.flags as flags
+from dbt.adapters.factory import get_adapter, reset_adapters, register_adapter
 from dbt.contracts.graph.manifest import Manifest
 from dbt.contracts.rpc import (
     LastParse,
@@ -126,6 +127,8 @@ def reload_manifest(self) -> bool:
     def reload_config(self):
         config = self.config.from_args(self.args)
         self.config = config
+        reset_adapters()
+        register_adapter(config)
         return config
 
     def add_request(self, request_handler: TaskHandlerProtocol):
@@ -184,7 +187,7 @@ def set_parsing(self) -> bool:
         return True
 
     def parse_manifest(self) -> None:
-        self.manifest = get_full_manifest(self.config)
+        self.manifest = get_full_manifest(self.config, reset=True)
 
     def set_compile_exception(self, exc, logs=List[LogMessage]) -> None:
         assert self.last_parse.state == ManifestStatus.Compiling, \
@@ -227,6 +230,7 @@ def get_handler(
             return None
 
         task = self.rpc_task(method)
+
         return task
 
     def task_table(self) -> List[TaskRow]:
diff --git a/core/dbt/task/rpc/cli.py b/core/dbt/task/rpc/cli.py
index e39d82ead92..a981783a0cf 100644
--- a/core/dbt/task/rpc/cli.py
+++ b/core/dbt/task/rpc/cli.py
@@ -104,7 +104,7 @@ def handle_request(self) -> Result:
         if dumped != self.args.vars:
             self.real_task.args.vars = dumped
             if isinstance(self.real_task, RemoteManifestMethod):
-                self.real_task.manifest = get_full_manifest(self.config)
+                self.real_task.manifest = get_full_manifest(self.config, reset=True)
 
         # we parsed args from the cli, so we're set on that front
         return self.real_task.handle_request()
diff --git a/core/dbt/utils.py b/core/dbt/utils.py
index 8f446cab665..aac730ebc51 100644
--- a/core/dbt/utils.py
+++ b/core/dbt/utils.py
@@ -320,7 +320,7 @@ def default(self, obj):
         if hasattr(obj, 'to_dict'):
             # if we have a to_dict we should try to serialize the result of
             # that!
-            obj = obj.to_dict()
+            return obj.to_dict()
         return super().default(obj)