diff --git a/src/saveload/afterload.cpp b/src/saveload/afterload.cpp
--- a/src/saveload/afterload.cpp
+++ b/src/saveload/afterload.cpp
@@ -1694,6 +1694,21 @@ bool AfterLoadGame()
 		}
 	}
 
+	if (CheckSavegameVersion(112)) {
+		for (TileIndex t = 0; t < map_size; t++) {
+			/* Check for HQ bit being set, instead of using map accessor,
+			 * since we've already changed it code-wise */
+			if (IsTileType(t, MP_UNMOVABLE) && HasBit(_m[t].m5, 7)) {
+				/* Move size and part identification of HQ out of the m5 attribute,
+				 * on new locations */
+				uint8 old_m5 = _m[t].m5;
+				_m[t].m5 = UNMOVABLE_HQ;
+				SetCompanyHQSize(t, GB(old_m5, 2, 3));
+				SetCompanyHQSection(t, GB(old_m5, 0, 2));
+			}
+		}
+	}
+
 	GamelogPrintDebug(1);
 
 	bool ret = InitializeWindowsAndCaches();