diff --git a/phosphor-regulators/src/actions/action_environment.hpp b/phosphor-regulators/src/actions/action_environment.hpp
index e519fa5..eb66981 100644
--- a/phosphor-regulators/src/actions/action_environment.hpp
+++ b/phosphor-regulators/src/actions/action_environment.hpp
@@ -15,9 +15,7 @@
  */
 #pragma once
 
-#include "device.hpp"
 #include "id_map.hpp"
-#include "rule.hpp"
 
 #include <cstddef> // for size_t
 #include <stdexcept>
@@ -26,6 +24,10 @@
 namespace phosphor::power::regulators
 {
 
+// Forward declarations to avoid circular dependencies
+class Device;
+class Rule;
+
 /**
  * @class ActionEnvironment
  *
@@ -198,7 +200,7 @@
     /**
      * Mapping from string IDs to the associated Device and Rule objects.
      */
-    const IDMap& idMap{};
+    const IDMap& idMap;
 
     /**
      * Current device ID.
diff --git a/phosphor-regulators/src/id_map.cpp b/phosphor-regulators/src/id_map.cpp
new file mode 100644
index 0000000..d39fa4f
--- /dev/null
+++ b/phosphor-regulators/src/id_map.cpp
@@ -0,0 +1,41 @@
+/**
+ * Copyright © 2019 IBM Corporation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "id_map.hpp"
+
+#include "device.hpp"
+#include "rail.hpp"
+#include "rule.hpp"
+
+namespace phosphor::power::regulators
+{
+
+void IDMap::addDevice(Device& device)
+{
+    deviceMap[device.getID()] = &device;
+}
+
+void IDMap::addRail(Rail& rail)
+{
+    railMap[rail.getID()] = &rail;
+}
+
+void IDMap::addRule(Rule& rule)
+{
+    ruleMap[rule.getID()] = &rule;
+}
+
+} // namespace phosphor::power::regulators
diff --git a/phosphor-regulators/src/id_map.hpp b/phosphor-regulators/src/id_map.hpp
index 2fbaa93..289c7a9 100644
--- a/phosphor-regulators/src/id_map.hpp
+++ b/phosphor-regulators/src/id_map.hpp
@@ -15,10 +15,6 @@
  */
 #pragma once
 
-#include "device.hpp"
-#include "rail.hpp"
-#include "rule.hpp"
-
 #include <map>
 #include <stdexcept>
 #include <string>
@@ -26,6 +22,11 @@
 namespace phosphor::power::regulators
 {
 
+// Forward declarations to avoid circular dependencies
+class Device;
+class Rail;
+class Rule;
+
 /**
  * @class IDMap
  *
@@ -48,30 +49,21 @@
      *
      * @param device device to add
      */
-    void addDevice(Device& device)
-    {
-        deviceMap[device.getID()] = &device;
-    }
+    void addDevice(Device& device);
 
     /**
      * Adds the specified rail to this IDMap.
      *
      * @param rail rail to add
      */
-    void addRail(Rail& rail)
-    {
-        railMap[rail.getID()] = &rail;
-    }
+    void addRail(Rail& rail);
 
     /**
      * Adds the specified rule to this IDMap.
      *
      * @param rule rule to add
      */
-    void addRule(Rule& rule)
-    {
-        ruleMap[rule.getID()] = &rule;
-    }
+    void addRule(Rule& rule);
 
     /**
      * Returns the device with the specified ID.
diff --git a/phosphor-regulators/src/meson.build b/phosphor-regulators/src/meson.build
index 23266b0..76551ae 100644
--- a/phosphor-regulators/src/meson.build
+++ b/phosphor-regulators/src/meson.build
@@ -2,3 +2,14 @@
     '.',
     'actions'
 )
+
+phosphor_regulators_source_files = [
+    'id_map.cpp'
+]
+
+phosphor_regulators_library = static_library(
+    'phosphor-regulators',
+    phosphor_regulators_source_files,
+    implicit_include_directories: false,
+    include_directories: phosphor_regulators_include_directories
+)
diff --git a/phosphor-regulators/test/id_map_tests.cpp b/phosphor-regulators/test/id_map_tests.cpp
index 7a1307a..5d47d7d 100644
--- a/phosphor-regulators/test/id_map_tests.cpp
+++ b/phosphor-regulators/test/id_map_tests.cpp
@@ -13,7 +13,10 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+#include "device.hpp"
 #include "id_map.hpp"
+#include "rail.hpp"
+#include "rule.hpp"
 
 #include <exception>
 #include <stdexcept>
diff --git a/phosphor-regulators/test/meson.build b/phosphor-regulators/test/meson.build
index a60249f..a246150 100644
--- a/phosphor-regulators/test/meson.build
+++ b/phosphor-regulators/test/meson.build
@@ -21,6 +21,7 @@
                     gmock,
                     gtest,
                 ],
+                link_with: phosphor_regulators_library,
                 implicit_include_directories: false,
                 include_directories: [
                     phosphor_regulators_include_directories,