diff --git a/src/js/backwardsCompatibility.js b/src/js/backwardsCompatibility.js
index 4b82f740dcf830eb0a43e4a915f47395f7374952..2cee9acac531cfb61fbbc470bfc2ff19eaae5d3d 100644
--- a/src/js/backwardsCompatibility.js
+++ b/src/js/backwardsCompatibility.js
@@ -3200,7 +3200,7 @@ window.backwardsCompatibility = (function() {
 
 			if (V.genePool.map(function(s) { return s.ID; }).count(_Slave.ID) > 1) {
 				/* first check for duplicate IDs, keep the first entry and delete the others */
-				for (let _bci2 = _bci + 1; _bci2 < V.genePool.length; _bci2) {
+				for (let _bci2 = _bci + 1; _bci2 < V.genePool.length; _bci2++) {
 					if (V.genePool[_bci2].ID === _Slave.ID) {
 						V.genePool.deleteAt(_bci2), _bci2--;
 					}
@@ -3229,7 +3229,7 @@ window.backwardsCompatibility = (function() {
 			}
 			if (_dontDeleteMe === 0) {
 				/* avoid going through this loop if possible */
-				for (let _bci2 = 0; _bci2 < V.slaves.length; _bci2) {
+				for (let _bci2 = 0; _bci2 < V.slaves.length; _bci2++) {
 					if (isImpregnatedBy(V.slaves[_bci2], _Slave)) {
 						/* have we impregnated a slave on the slaves array? */
 						_dontDeleteMe = 1;
@@ -3285,7 +3285,7 @@ window.backwardsCompatibility = (function() {
 		}
 
 		if (V.nurseryNannies > 0) {
-			for (let _bci = 0; _bci < V.cribs.length; _bci) {
+			for (let _bci = 0; _bci < V.cribs.length; _bci++) {
 				App.Update.Slave(V.cribs[_bci]);
 				// let _nurseryChild = V.cribs[_bci]; TODO: on importing this to JS, what is this even supposed to do?
 			}