diff --git a/amplpy/ampl.py b/amplpy/ampl.py
index 0a5e37e..b0c48ae 100644
--- a/amplpy/ampl.py
+++ b/amplpy/ampl.py
@@ -1,5 +1,6 @@
 # -*- coding: utf-8 -*-
 import sys
+import os
 from numbers import Real
 
 from .errorhandler import ErrorHandler
@@ -100,6 +101,11 @@ def __init__(self, environment=None, langext=None):
         try:
             if environment is None:
                 self._impl = amplpython.AMPL()
+                if os.name == "nt":
+                    # Workaround for Windows issue with environment variables
+                    ampl_libpath = os.environ.get("ampl_libpath", "")
+                    if ampl_libpath:
+                        self._impl.setOption("ampl_libpath", ampl_libpath)
             else:
                 self._impl = amplpython.AMPL(environment._impl)
         except RuntimeError as exp:
diff --git a/amplpy/environment.py b/amplpy/environment.py
index 5ee7f58..2a6a3cc 100644
--- a/amplpy/environment.py
+++ b/amplpy/environment.py
@@ -2,6 +2,7 @@
 from .iterators import EnvIterator
 from .base import BaseClass
 from . import amplpython
+import os
 
 
 class Environment(BaseClass):
@@ -24,9 +25,13 @@ def __init__(self, binary_directory=None, binary_name=None):
             binary_directory = ""
         if binary_name is None:
             binary_name = ""
-        super(Environment, self).__init__(
-            amplpython.Environment(binary_directory, binary_name)
-        )
+        _impl = amplpython.Environment(binary_directory, binary_name)
+        if os.name == "nt":
+            # Workaround for Windows issue with environment variables
+            ampl_libpath = os.environ.get("ampl_libpath", "")
+            if ampl_libpath:
+                _impl.put("ampl_libpath", ampl_libpath)
+        super(Environment, self).__init__(_impl)
 
     def __iter__(self):
         return EnvIterator(self._impl)