diff --git a/src/deficiency.js b/src/deficiency.js
index be66bd09..ec02051e 100644
--- a/src/deficiency.js
+++ b/src/deficiency.js
@@ -155,9 +155,9 @@ const TRIT = [
 ];
 
 const deficiency = (lut, t) => {
-	let tt = Math.max(0, Math.min(1, t));
-	let i = Math.round(tt / 0.1);
-	let w = Math.round(tt % 0.1);
+	let tt = Math.max(0, Math.min(1, t)) * (lut.length - 1);
+	let i = Math.floor(tt);
+	let w = tt - i;
 	let arr = lut[i];
 	if (w > 0 && i < lut.length - 1) {
 		let arr_2 = lut[i + 1];
diff --git a/test/deficiency.test.js b/test/deficiency.test.js
index c05d12af..cb176a53 100644
--- a/test/deficiency.test.js
+++ b/test/deficiency.test.js
@@ -14,9 +14,13 @@ test('0 severity', t => {
 });
 
 test('0.55 severity', t => {
-	assert.equal(formatHex(filterDeficiencyProt(0.55)('blue')), '#0012ff');
+	assert.equal(formatHex(filterDeficiencyProt(0.55)('blue')), '#0011ff');
 	assert.equal(formatHex(filterDeficiencyDeuter(0.55)('blue')), '#000afa');
-	assert.equal(formatHex(filterDeficiencyTrit(0.55)('blue')), '#000fae');
+	assert.equal(formatHex(filterDeficiencyTrit(0.55)('blue')), '#000eb6');
+});
+
+test('severity interpolates between matrices', t => {
+	assert.equal(formatHex(filterDeficiencyProt(0.05)('#ff8800')), '#f98900');
 });
 
 test('1 severity', t => {