diff --git a/CMakeLists.txt b/CMakeLists.txt
index 76797bf8..21e7f793 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -200,7 +200,6 @@ set(LIBLOOT_SRC_API_CPP_FILES
     "${CMAKE_SOURCE_DIR}/src/api/api_database.cpp"
     "${CMAKE_SOURCE_DIR}/src/api/bsa.cpp"
     "${CMAKE_SOURCE_DIR}/src/api/exception/cyclic_interaction_error.cpp"
-    "${CMAKE_SOURCE_DIR}/src/api/exception/error_categories.cpp"
     "${CMAKE_SOURCE_DIR}/src/api/exception/undefined_group_error.cpp"
     "${CMAKE_SOURCE_DIR}/src/api/metadata/condition_evaluator.cpp"
     "${CMAKE_SOURCE_DIR}/src/api/metadata/conditional_metadata.cpp"
@@ -231,8 +230,8 @@ set(LIBLOOT_INCLUDE_H_FILES
     "${CMAKE_SOURCE_DIR}/include/loot/api.h"
     "${CMAKE_SOURCE_DIR}/include/loot/api_decorator.h"
     "${CMAKE_SOURCE_DIR}/include/loot/database_interface.h"
-    "${CMAKE_SOURCE_DIR}/include/loot/exception/error_categories.h"
     "${CMAKE_SOURCE_DIR}/include/loot/exception/cyclic_interaction_error.h"
+    "${CMAKE_SOURCE_DIR}/include/loot/exception/plugin_not_loaded_error.h"
     "${CMAKE_SOURCE_DIR}/include/loot/exception/undefined_group_error.h"
     "${CMAKE_SOURCE_DIR}/include/loot/enum/edge_type.h"
     "${CMAKE_SOURCE_DIR}/include/loot/enum/game_type.h"
diff --git a/docs/api/reference.rst b/docs/api/reference.rst
index fa110b1d..fbeef358 100644
--- a/docs/api/reference.rst
+++ b/docs/api/reference.rst
@@ -95,13 +95,8 @@ Exceptions
 .. doxygenclass:: loot::CyclicInteractionError
    :members:
 
-.. doxygenclass:: loot::UndefinedGroupError
+.. doxygenclass:: loot::PluginNotLoadedError
    :members:
 
-Error Categories
-================
-
-LOOT uses error category objects to identify errors with codes that originate in
-lower-level libraries.
-
-.. doxygenfunction:: loot::esplugin_category
+.. doxygenclass:: loot::UndefinedGroupError
+   :members:
diff --git a/include/loot/api.h b/include/loot/api.h
index abdd10eb..a08320b1 100644
--- a/include/loot/api.h
+++ b/include/loot/api.h
@@ -35,7 +35,7 @@
 #include "loot/enum/game_type.h"
 #include "loot/enum/log_level.h"
 #include "loot/exception/cyclic_interaction_error.h"
-#include "loot/exception/error_categories.h"
+#include "loot/exception/plugin_not_loaded_error.h"
 #include "loot/exception/undefined_group_error.h"
 #include "loot/game_interface.h"
 #include "loot/loot_version.h"
diff --git a/include/loot/exception/error_categories.h b/include/loot/exception/plugin_not_loaded_error.h
similarity index 67%
rename from include/loot/exception/error_categories.h
rename to include/loot/exception/plugin_not_loaded_error.h
index d5c005c8..1743f2c2 100644
--- a/include/loot/exception/error_categories.h
+++ b/include/loot/exception/plugin_not_loaded_error.h
@@ -22,21 +22,20 @@
     <https://www.gnu.org/licenses/>.
     */
 
-#ifndef LOOT_ERROR_CATEGORIES
-#define LOOT_ERROR_CATEGORIES
+#ifndef LOOT_EXCEPTION_PLUGIN_NOT_LOADED_ERROR
+#define LOOT_EXCEPTION_PLUGIN_NOT_LOADED_ERROR
 
-#include <system_error>
-
-#include "loot/api_decorator.h"
+#include <stdexcept>
 
 namespace loot {
 /**
- * @brief Get the error category that can be used to identify system_error
- *        exceptions that are due to esplugin errors.
- * @returns A reference to the static object of unspecified runtime type,
- *          derived from std::error_category.
+ * @brief An exception class thrown if a plugin that must be loaded hasn't been
+ *        loaded.
  */
-LOOT_API const std::error_category& esplugin_category();
+class PluginNotLoadedError : public std::runtime_error {
+public:
+  using std::runtime_error::runtime_error;
+};
 }
 
 #endif
diff --git a/src/api/exception/error_categories.cpp b/src/api/exception/error_categories.cpp
deleted file mode 100644
index c6035f07..00000000
--- a/src/api/exception/error_categories.cpp
+++ /dev/null
@@ -1,46 +0,0 @@
-/*  LOOT
-
-    A load order optimisation tool for Oblivion, Skyrim, Fallout 3 and
-    Fallout: New Vegas.
-
-    Copyright (C) 2012-2016    WrinklyNinja
-
-    This file is part of LOOT.
-
-    LOOT is free software: you can redistribute
-    it and/or modify it under the terms of the GNU General Public License
-    as published by the Free Software Foundation, either version 3 of
-    the License, or (at your option) any later version.
-
-    LOOT is distributed in the hope that it will
-    be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU General Public License for more details.
-
-    You should have received a copy of the GNU General Public License
-    along with LOOT.  If not, see
-    <https://www.gnu.org/licenses/>.
-    */
-
-#include "loot/exception/error_categories.h"
-
-#include <string>
-
-namespace loot {
-namespace detail {
-class esplugin_category : public std::error_category {
-  const char* name() const noexcept override { return "esplugin"; }
-
-  std::string message(int) const override { return "esplugin error"; }
-
-  bool equivalent(const std::error_code& code, int) const noexcept override {
-    return code.category().name() == name();
-  }
-};
-}
-
-LOOT_API const std::error_category& esplugin_category() {
-  static detail::esplugin_category instance;
-  return instance;
-}
-}
diff --git a/src/api/plugin.cpp b/src/api/plugin.cpp
index 48056dd2..2aae36b7 100644
--- a/src/api/plugin.cpp
+++ b/src/api/plugin.cpp
@@ -34,7 +34,7 @@
 #include "api/helpers/crc.h"
 #include "api/helpers/logging.h"
 #include "api/helpers/text.h"
-#include "loot/exception/error_categories.h"
+#include "loot/exception/plugin_not_loaded_error.h"
 
 namespace {
 using loot::BSA_FILE_EXTENSION;
@@ -170,14 +170,14 @@ void HandleEspluginError(unsigned int returnCode, std::string_view operation) {
   }
 
   auto err = fmt::format(
-      "esplugin failed to {}. Error code: {}", operation, returnCode);
+      "Failed to {}. esplugin error code: {}", operation, returnCode);
 
-  const char* e = nullptr;
-  esp_get_error_message(&e);
-  if (e == nullptr) {
+  const char* message = nullptr;
+  esp_get_error_message(&message);
+  if (message == nullptr) {
     err += ". Details could not be fetched.";
   } else {
-    err += ". Details: " + std::string(e);
+    err += ". Details: " + std::string(message);
   }
 
   auto logger = loot::getLogger();
@@ -185,7 +185,11 @@ void HandleEspluginError(unsigned int returnCode, std::string_view operation) {
     logger->error(err);
   }
 
-  throw std::system_error(returnCode, loot::esplugin_category(), err);
+  if (returnCode == ESP_ERROR_PLUGIN_METADATA_NOT_FOUND) {
+    throw loot::PluginNotLoadedError(err);
+  }
+
+  throw std::runtime_error(err);
 }
 
 template<typename... Args>
@@ -268,10 +272,6 @@ Plugin::Plugin(const GameType gameType,
     tags_ = ExtractBashTags(description);
     version_ = ExtractVersion(description);
   } catch (const std::system_error& e) {
-    if (e.code().category() == esplugin_category()) {
-      throw;
-    }
-
     if (logger) {
       logger->error("Cannot read plugin file \"{}\". Details: {}",
                     pluginPath.u8string(),
diff --git a/src/tests/api/interface/game_interface_test.h b/src/tests/api/interface/game_interface_test.h
index 6e4abe91..0a1173d0 100644
--- a/src/tests/api/interface/game_interface_test.h
+++ b/src/tests/api/interface/game_interface_test.h
@@ -371,13 +371,8 @@ TEST_P(
 
   if (GetParam() == GameType::tes3 || GetParam() == GameType::openmw ||
       GetParam() == GameType::starfield) {
-    try {
-      handle_->LoadPlugins({blankMasterDependentEsm}, false);
-      FAIL();
-    } catch (const std::system_error& e) {
-      EXPECT_EQ(ESP_ERROR_PLUGIN_METADATA_NOT_FOUND, e.code().value());
-      EXPECT_EQ(esplugin_category(), e.code().category());
-    }
+    EXPECT_THROW(handle_->LoadPlugins({blankMasterDependentEsm}, false),
+                 PluginNotLoadedError);
   } else {
     handle_->LoadPlugins({blankMasterDependentEsm}, false);
 
@@ -390,13 +385,8 @@ TEST_P(
     loadPluginsShouldThrowIfAPluginHasAMasterThatIsNotInTheInputAndIsNotAlreadyLoadedAndGameIsMorrowindOrStarfield) {
   if (GetParam() == GameType::tes3 || GetParam() == GameType::openmw ||
       GetParam() == GameType::starfield) {
-    try {
-      handle_->LoadPlugins({blankMasterDependentEsm}, false);
-      FAIL();
-    } catch (const std::system_error& e) {
-      EXPECT_EQ(ESP_ERROR_PLUGIN_METADATA_NOT_FOUND, e.code().value());
-      EXPECT_EQ(esplugin_category(), e.code().category());
-    }
+    EXPECT_THROW(handle_->LoadPlugins({blankMasterDependentEsm}, false),
+                 PluginNotLoadedError);
   } else {
     handle_->LoadPlugins({blankMasterDependentEsm}, false);
 
diff --git a/src/tests/api/internals/plugin_test.h b/src/tests/api/internals/plugin_test.h
index b9151cba..a248d66f 100644
--- a/src/tests/api/internals/plugin_test.h
+++ b/src/tests/api/internals/plugin_test.h
@@ -27,7 +27,7 @@ along with LOOT.  If not, see
 
 #include "api/game/game.h"
 #include "api/plugin.h"
-#include "loot/exception/error_categories.h"
+#include "loot/exception/plugin_not_loaded_error.h"
 #include "tests/common_game_test_fixture.h"
 
 namespace loot {
@@ -328,7 +328,7 @@ TEST_P(PluginTest, loadingWholePluginShouldSucceedForOpenMWPlugins) {
   } else {
     EXPECT_THROW(
         Plugin(game_.GetType(), game_.GetCache(), dataPath / omwscripts, false),
-        std::system_error);
+        std::runtime_error);
   }
 }
 
@@ -354,16 +354,11 @@ TEST_P(
 }
 
 TEST_P(PluginTest, loadingAPluginThatDoesNotExistShouldThrow) {
-  try {
-    Plugin(game_.GetType(),
-           game_.GetCache(),
-           game_.DataPath() / "Blank\\.esp",
-           true);
-    FAIL();
-  } catch (const std::system_error& e) {
-    EXPECT_EQ(ESP_ERROR_FILE_NOT_FOUND, e.code().value());
-    EXPECT_EQ(esplugin_category(), e.code().category());
-  }
+  EXPECT_THROW(Plugin(game_.GetType(),
+                      game_.GetCache(),
+                      game_.DataPath() / "Blank\\.esp",
+                      true),
+               std::runtime_error);
 }
 
 TEST_P(PluginTest, isValidShouldReturnTrueForAValidPlugin) {