diff --git a/src/saveload/extended_ver_sl.cpp b/src/saveload/extended_ver_sl.cpp
index 19aa3ccb70..b008370bf1 100644
--- a/src/saveload/extended_ver_sl.cpp
+++ b/src/saveload/extended_ver_sl.cpp
@@ -197,71 +197,71 @@ void SlXvCheckSpecialSavegameVersions()
 	// Checks for special savegame versions go here
 	extern SaveLoadVersion _sl_version;
 
-	if (_sl_version == 2000) {
+	if (_sl_version == SL_TRACE_RESTRICT_2000) {
 		DEBUG(sl, 1, "Loading a trace restrict patch savegame version %d as version 194", _sl_version);
-		_sl_version = (SaveLoadVersion) 194;
+		_sl_version = SLV_194;
 		_sl_is_faked_ext = true;
 		_sl_xv_feature_versions[XSLFI_TRACE_RESTRICT] = 1;
 	}
-	if (_sl_version == 2001) {
+	if (_sl_version == SL_TRACE_RESTRICT_2001) {
 		DEBUG(sl, 1, "Loading a trace restrict patch savegame version %d as version 195", _sl_version);
-		_sl_version = (SaveLoadVersion) 195;
+		_sl_version = SLV_195;
 		_sl_is_faked_ext = true;
 		_sl_xv_feature_versions[XSLFI_TRACE_RESTRICT] = 6;
 	}
-	if (_sl_version == 2002) {
+	if (_sl_version == SL_TRACE_RESTRICT_2002) {
 		DEBUG(sl, 1, "Loading a trace restrict patch savegame version %d as version 196", _sl_version);
-		_sl_version = (SaveLoadVersion) 196;
+		_sl_version = SLV_196;
 		_sl_is_faked_ext = true;
 		_sl_xv_feature_versions[XSLFI_TRACE_RESTRICT] = 6;
 	}
 
-	if (_sl_version == 220) { /* SL_SPRING_2013_v2_0_102 */
+	if (_sl_version == SL_SPRING_2013_v2_0_102) { /* 220 */
 		DEBUG(sl, 1, "Loading a SpringPP 2013 v2.0.102 savegame version %d as version 187", _sl_version);
 
-		_sl_version = (SaveLoadVersion) 187;
+		_sl_version = SLV_187;
 		_sl_is_faked_ext = true;
 		_sl_xv_feature_versions[XSLFI_SPRINGPP] = 1;
-	} else if (_sl_version == 221) { /* SL_SPRING_2013_v2_1_108 */
+	} else if (_sl_version == SL_SPRING_2013_v2_1_108) { /* 221 */
 		DEBUG(sl, 1, "Loading a SpringPP 2013 v2.1.108 savegame version %d as version 188", _sl_version);
 
-		_sl_version = (SaveLoadVersion) 188;
+		_sl_version = SLV_188;
 		_sl_is_faked_ext = true;
 		_sl_xv_feature_versions[XSLFI_SPRINGPP] = 2;
-	} else if (_sl_version == 222) { /* SL_SPRING_2013_v2_1_147 */
+	} else if (_sl_version == SL_SPRING_2013_v2_1_147) { /* 222 */
 		DEBUG(sl, 1, "Loading a SpringPP 2013 v2.1.147 savegame version %d as version 194", _sl_version);
 
-		_sl_version = (SaveLoadVersion) 194;
+		_sl_version = SLV_194;
 		_sl_is_faked_ext = true;
 		_sl_xv_feature_versions[XSLFI_SPRINGPP] = 4; // Note that this break in numbering is deliberate
-	} else if (_sl_version == 223) { /* SL_SPRING_2013_v2_3_XXX */
+	} else if (_sl_version == SL_SPRING_2013_v2_3_XXX) { /* 223 */
 		DEBUG(sl, 1, "Loading a SpringPP 2013 v2.3.xxx savegame version %d as version 194", _sl_version);
 
-		_sl_version = (SaveLoadVersion) 194;
+		_sl_version = SLV_194;
 		_sl_is_faked_ext = true;
 		_sl_xv_feature_versions[XSLFI_SPRINGPP] = 3; // Note that this break in numbering is deliberate
-	} else if (_sl_version == 224) { /* SL_SPRING_2013_v2_3_b3 */
+	} else if (_sl_version == SL_SPRING_2013_v2_3_b3) { /* 224 */
 		DEBUG(sl, 1, "Loading a SpringPP 2013 v2.3.b3 savegame version %d as version 194", _sl_version);
 
-		_sl_version = (SaveLoadVersion) 194;
+		_sl_version = SLV_194;
 		_sl_is_faked_ext = true;
 		_sl_xv_feature_versions[XSLFI_SPRINGPP] = 5;
-	} else if (_sl_version == 225) { /* SL_SPRING_2013_v2_3_b4 */
+	} else if (_sl_version == SL_SPRING_2013_v2_3_b4) { /* 225 */
 		DEBUG(sl, 1, "Loading a SpringPP 2013 v2.3.b4 savegame version %d as version 194", _sl_version);
 
-		_sl_version = (SaveLoadVersion) 194;
+		_sl_version = SLV_194;
 		_sl_is_faked_ext = true;
 		_sl_xv_feature_versions[XSLFI_SPRINGPP] = 6;
-	} else if (_sl_version == 226) { /* SL_SPRING_2013_v2_3_b5 */
+	} else if (_sl_version == SL_SPRING_2013_v2_3_b5) { /* 226 */
 		DEBUG(sl, 1, "Loading a SpringPP 2013 v2.3.b5 savegame version %d as version 195", _sl_version);
 
-		_sl_version = (SaveLoadVersion) 195;
+		_sl_version = SLV_195;
 		_sl_is_faked_ext = true;
 		_sl_xv_feature_versions[XSLFI_SPRINGPP] = 7;
-	} else if (_sl_version == 227) { /* SL_SPRING_2013_v2_4 */
+	} else if (_sl_version == SL_SPRING_2013_v2_4) { /* 227 */
 		DEBUG(sl, 1, "Loading a SpringPP 2013 v2.4 savegame version %d as version 195", _sl_version);
 
-		_sl_version = (SaveLoadVersion) 195;
+		_sl_version = SLV_195;
 		_sl_is_faked_ext = true;
 		_sl_xv_feature_versions[XSLFI_SPRINGPP] = 8;
 	}
diff --git a/src/saveload/saveload.h b/src/saveload/saveload.h
index 4991b6bd39..e03b1dd407 100644
--- a/src/saveload/saveload.h
+++ b/src/saveload/saveload.h
@@ -303,6 +303,18 @@ enum SaveLoadVersion : uint16 {
 	SLV_TREES_WATER_CLASS,                  ///< 213  PR#7405 WaterClass update for tree tiles.
 
 	SL_MAX_VERSION,                         ///< Highest possible saveload version
+
+	SL_SPRING_2013_v2_0_102 = 220,
+	SL_SPRING_2013_v2_1_108 = 221,
+	SL_SPRING_2013_v2_1_147 = 222,
+	SL_SPRING_2013_v2_3_XXX = 223,
+	SL_SPRING_2013_v2_3_b3 = 224,
+	SL_SPRING_2013_v2_3_b4 = 225,
+	SL_SPRING_2013_v2_3_b5 = 226,
+	SL_SPRING_2013_v2_4 = 227,
+	SL_TRACE_RESTRICT_2000 = 2000,
+	SL_TRACE_RESTRICT_2001 = 2001,
+	SL_TRACE_RESTRICT_2002 = 2002,
 };
 
 /** Save or load result codes. */