diff --git a/com.rlabrecque.steamworks.net/Editor/RedistInstall.cs b/com.rlabrecque.steamworks.net/Editor/RedistInstall.cs
index 141fd47b..4a7fa0e5 100644
--- a/com.rlabrecque.steamworks.net/Editor/RedistInstall.cs
+++ b/com.rlabrecque.steamworks.net/Editor/RedistInstall.cs
@@ -5,13 +5,14 @@
 using UnityEngine;
 using UnityEditor;
 using System.IO;
+using System.Collections.Generic;
 
 // This copys various files into their required locations when Unity is launched to make installation a breeze.
 [InitializeOnLoad]
 public class RedistInstall {
 	static RedistInstall() {
 		WriteSteamAppIdTxtFile();
-
+		AddDefineSymbols();
 		CheckForOldDlls();
 	}
 
@@ -54,4 +55,16 @@ static void CheckForOldDlls() {
 			Debug.LogError("[Steamworks.NET] Please delete the old version of 'steam_api64.dll' in your project root before continuing.");
 		}
 	}
+
+	static void AddDefineSymbols() {
+		string currentDefines = PlayerSettings.GetScriptingDefineSymbolsForGroup(EditorUserBuildSettings.selectedBuildTargetGroup);
+		HashSet<string> defines = new HashSet<string>(currentDefines.Split(';')) {
+			"STEAMWORKS_NET"
+		};
+
+		string newDefines = string.Join(";", defines);
+		if (newDefines != currentDefines) {
+			PlayerSettings.SetScriptingDefineSymbolsForGroup(EditorUserBuildSettings.selectedBuildTargetGroup, newDefines);
+		}
+	}
 }