diff --git a/assets/src/scripts/monitoring-location/components/hydrograph/selectors/domain.js b/assets/src/scripts/monitoring-location/components/hydrograph/selectors/domain.js
index dab1eaf852ebfca596794d5c82d8e3826a9297d4..c2198c19f75640c7deb01e91af31734806b731b6 100644
--- a/assets/src/scripts/monitoring-location/components/hydrograph/selectors/domain.js
+++ b/assets/src/scripts/monitoring-location/components/hydrograph/selectors/domain.js
@@ -283,4 +283,3 @@ const getYTickDetails = memoize(tickKind => createSelector(
 
 export const getSecondaryYAxisTickDetails = getYTickDetails('secondary');
 export const getPrimaryYAxisTickDetails = getYTickDetails('primary');
-
diff --git a/assets/src/scripts/monitoring-location/components/hydrograph/selectors/domain.test.js b/assets/src/scripts/monitoring-location/components/hydrograph/selectors/domain.test.js
index fbd2030b48f4842b13dd37becf3582b0b9eb5ad2..f48ce35757461e38a064358490be07b6e8c59555 100644
--- a/assets/src/scripts/monitoring-location/components/hydrograph/selectors/domain.test.js
+++ b/assets/src/scripts/monitoring-location/components/hydrograph/selectors/domain.test.js
@@ -6,7 +6,8 @@ import {
 } from '../mock-hydrograph-state';
 import {
     extendDomain,
-    getYTickDetails,
+    getPrimaryYAxisTickDetails,
+    getSecondaryYAxisTickDetails,
     getFullArrayOfAdditionalTickMarks,
     getLowestAbsoluteValueOfTickValues,
     getRoundedTickValues,
@@ -64,16 +65,32 @@ describe('monitoring-location/components/hydrograph/selectors/domain module', ()
         });
     });
 
-    describe('getYTickDetails', () => {
+    describe('getPrimaryYAxisTickDetails', () => {
         it('Returns the default tick details if no parameter is defined', () => {
-            const tickDetails = getYTickDetails.resultFunc([0, 1], null);
+            const tickDetails = getPrimaryYAxisTickDetails.resultFunc([0, 1], null);
             expect(tickDetails.tickValues).toEqual(expect.any(Array));
             expect(tickDetails.tickFormat).toEqual(expect.any(Function));
             expect(tickDetails.tickFormat(1)).toEqual(expect.any(String));
         });
 
         it('returns ticks and a formatting function', () => {
-            const tickDetails = getYTickDetails.resultFunc([0, 1], {parameterCode: '00065'});
+            const tickDetails = getPrimaryYAxisTickDetails.resultFunc([0, 1], {parameterCode: '00065'});
+            expect(tickDetails.tickValues).toEqual(expect.any(Array));
+            expect(tickDetails.tickFormat).toEqual(expect.any(Function));
+            expect(tickDetails.tickFormat(1)).toEqual(expect.any(String));
+        });
+    });
+
+    describe('getSecondaryYAxisTickDetails', () => {
+        it('Returns the default tick details if no parameter is defined', () => {
+            const tickDetails = getSecondaryYAxisTickDetails.resultFunc([0, 1], null, [0, 1], null);
+            expect(tickDetails.tickValues).toEqual(expect.any(Array));
+            expect(tickDetails.tickFormat).toEqual(expect.any(Function));
+            expect(tickDetails.tickFormat(1)).toEqual(expect.any(String));
+        });
+
+        it('returns ticks and a formatting function', () => {
+            const tickDetails = getSecondaryYAxisTickDetails.resultFunc([0, 1], null, [0, 1], {parameterCode: '00065'});
             expect(tickDetails.tickValues).toEqual(expect.any(Array));
             expect(tickDetails.tickFormat).toEqual(expect.any(Function));
             expect(tickDetails.tickFormat(1)).toEqual(expect.any(String));