diff --git a/numba_cuda/numba/cuda/api.py b/numba_cuda/numba/cuda/api.py
index a0c5dc45e..cf63bd4f3 100644
--- a/numba_cuda/numba/cuda/api.py
+++ b/numba_cuda/numba/cuda/api.py
@@ -508,6 +508,11 @@ def close():
     Explicitly clears all contexts in the current thread, and destroys all
     contexts if the current thread is the main thread.
     """
+    # Must clear memsys object in case it has been used already
+    from .memory_management import rtsys
+
+    rtsys.close()
+
     devices.reset()
 
 
diff --git a/numba_cuda/numba/cuda/memory_management/nrt.py b/numba_cuda/numba/cuda/memory_management/nrt.py
index dac3ec746..8b31969fb 100644
--- a/numba_cuda/numba/cuda/memory_management/nrt.py
+++ b/numba_cuda/numba/cuda/memory_management/nrt.py
@@ -69,10 +69,18 @@ def __new__(cls, *args, **kwargs):
 
     def __init__(self):
         """Initialize memsys module and variable"""
+        self._reset()
+
+    def _reset(self):
+        """Reset to the uninitialized state"""
         self._memsys_module = None
         self._memsys = None
         self._initialized = False
 
+    def close(self):
+        """Close and reset"""
+        self._reset()
+
     def _compile_memsys_module(self):
         """
         Compile memsys.cu and create a module from it in the current context