diff --git a/.editorconfig b/.editorconfig
index f4eea3711f..543fe960b8 100644
--- a/.editorconfig
+++ b/.editorconfig
@@ -974,6 +974,9 @@ dotnet_diagnostic.RCS1048.severity = warning
 # Simplify boolean comparison.
 dotnet_diagnostic.RCS1049.severity = warning
 
+# Use compound assignment.
+dotnet_diagnostic.RCS1058.severity = warning
+
 # Avoid locking on publicly accessible instance.
 dotnet_diagnostic.RCS1059.severity = warning
 
diff --git a/OpenRA.Game/Support/MersenneTwister.cs b/OpenRA.Game/Support/MersenneTwister.cs
index e31bd0ad59..9c217a79a5 100644
--- a/OpenRA.Game/Support/MersenneTwister.cs
+++ b/OpenRA.Game/Support/MersenneTwister.cs
@@ -79,7 +79,7 @@ namespace OpenRA.Support
 					var y = (mt[i] & 0x80000000) | (mt[(i + 1) % 624] & 0x7fffffff);
 					mt[i] = mt[(i + 397u) % 624u] ^ (y >> 1);
 					if ((y & 1) == 1)
-						mt[i] = mt[i] ^ 2567483615;
+						mt[i] ^= 2567483615;
 				}
 			}
 		}
diff --git a/OpenRA.Mods.Cnc/FileFormats/BlowfishKeyProvider.cs b/OpenRA.Mods.Cnc/FileFormats/BlowfishKeyProvider.cs
index 3c68af3884..2d00dd1bc3 100644
--- a/OpenRA.Mods.Cnc/FileFormats/BlowfishKeyProvider.cs
+++ b/OpenRA.Mods.Cnc/FileFormats/BlowfishKeyProvider.cs
@@ -149,7 +149,7 @@ namespace OpenRA.Mods.Cnc.FileFormats
 
 			if (bits == 0) return;
 			for (i = 0; i < len - 1; i++) n[i] = (n[i] >> bits) | (n[i + 1] << (32 - bits));
-			n[i] = n[i] >> bits;
+			n[i] >>= bits;
 		}
 
 		static void ShlBigNum(uint[] n, int bits, int len)
diff --git a/OpenRA.Mods.D2k/Traits/World/BuildableTerrainLayer.cs b/OpenRA.Mods.D2k/Traits/World/BuildableTerrainLayer.cs
index 0a4c30f5e5..d8c4cf405f 100644
--- a/OpenRA.Mods.D2k/Traits/World/BuildableTerrainLayer.cs
+++ b/OpenRA.Mods.D2k/Traits/World/BuildableTerrainLayer.cs
@@ -82,7 +82,7 @@ namespace OpenRA.Mods.D2k.Traits
 			if (world.ActorMap.GetActorsAt(cell).Any(a => a.TraitOrDefault<Building>() != null))
 				return;
 
-			strength[cell] = strength[cell] - damage;
+			strength[cell] -= damage;
 			if (strength[cell] < 1)
 				RemoveTile(cell);
 		}