diff --git a/packages/@pollyjs/adapter/src/utils/dehumanize-time.js b/packages/@pollyjs/adapter/src/utils/dehumanize-time.js
new file mode 100644
index 00000000..0dee82f5
--- /dev/null
+++ b/packages/@pollyjs/adapter/src/utils/dehumanize-time.js
@@ -0,0 +1,47 @@
+const ALPHA_NUMERIC_DOT = /([0-9.]+)([a-zA-Z]+)/g;
+const TIMES = {
+  ms: 1,
+  millisecond: 1,
+  milliseconds: 1,
+  s: 1000,
+  sec: 1000,
+  secs: 1000,
+  second: 1000,
+  seconds: 1000,
+  m: 60000,
+  min: 60000,
+  mins: 60000,
+  minute: 60000,
+  minutes: 60000,
+  h: 3600000,
+  hr: 3600000,
+  hrs: 3600000,
+  hour: 3600000,
+  hours: 3600000,
+  d: 86400000,
+  day: 86400000,
+  days: 86400000,
+  w: 604800000,
+  wk: 604800000,
+  wks: 604800000,
+  week: 604800000,
+  weeks: 604800000,
+  y: 31536000000,
+  yr: 31536000000,
+  yrs: 31536000000,
+  year: 31536000000,
+  years: 31536000000
+};
+
+export default function dehumanizeTime(input) {
+  if (typeof input !== 'string') {
+    return NaN;
+  }
+
+  const parts = input.replace(/ /g, '').match(ALPHA_NUMERIC_DOT);
+  const sets = parts.map(part => part.split(ALPHA_NUMERIC_DOT).filter(o => o));
+
+  return sets.reduce((accum, [number, unit]) => {
+    return accum + parseFloat(number) * TIMES[unit];
+  }, 0);
+}
diff --git a/packages/@pollyjs/adapter/src/utils/human-time-to-ms.js b/packages/@pollyjs/adapter/src/utils/human-time-to-ms.js
deleted file mode 100644
index 70e595a3..00000000
--- a/packages/@pollyjs/adapter/src/utils/human-time-to-ms.js
+++ /dev/null
@@ -1,41 +0,0 @@
-const labelsToOffset = [
-  ['ms', 'millisecond', 'milliseconds', 1],
-  ['s', 'sec', 'secs', 'second', 'seconds', 1000],
-  ['m', 'min', 'mins', 'minute', 'minutes', 1000 * 60],
-  ['h', 'hr', 'hrs', 'hour', 'hours', 1000 * 60 * 60],
-  ['d', 'day', 'days', 1000 * 60 * 60 * 24],
-  ['w', 'wk', 'wks', 'week', 'weeks', 1000 * 60 * 60 * 24 * 7],
-  ['y', 'yr', 'yrs', 'year', 'years', 1000 * 60 * 60 * 24 * 365]
-];
-
-const times = labelsToOffset.reduce((accum, labels) => {
-  const labelOffset = labels.pop();
-
-  labels.forEach(label => (accum[label] = labelOffset));
-
-  return accum;
-}, {});
-
-export default function humanTimeToMilliseconds(humanTimeString) {
-  const fragments = (humanTimeString || '')
-    .replace(/[\W_]+/g, '') // remove non-alphanumeric characters
-    .split(/(\d+)/g);
-
-  fragments.shift();
-
-  const parsedFragments = fragments.reduce((accum, cur, i) => {
-    if (i % 2 === 0) {
-      accum.push([parseFloat(cur, 10)]);
-    } else {
-      accum[accum.length - 1].push(cur);
-    }
-
-    return accum;
-  }, []);
-
-  return parsedFragments.reduce((accum, [num, label]) => {
-    accum += num * times[label];
-
-    return accum;
-  }, 0);
-}
diff --git a/packages/@pollyjs/adapter/src/utils/is-expired.js b/packages/@pollyjs/adapter/src/utils/is-expired.js
index bf0853ce..6fe66929 100644
--- a/packages/@pollyjs/adapter/src/utils/is-expired.js
+++ b/packages/@pollyjs/adapter/src/utils/is-expired.js
@@ -1,10 +1,10 @@
-import calculateTime from './human-time-to-ms';
+import dehumanizeTime from './dehumanize-time';
 
 export default function isExpired(recordedOn, expiresIn) {
   if (recordedOn && expiresIn) {
     return (
       new Date() >
-      new Date(new Date(recordedOn).getTime() + calculateTime(expiresIn))
+      new Date(new Date(recordedOn).getTime() + dehumanizeTime(expiresIn))
     );
   }
 
diff --git a/packages/@pollyjs/adapter/tests/unit/utils/human-time-to-ms-test.js b/packages/@pollyjs/adapter/tests/unit/utils/dehumanize-time.js
similarity index 55%
rename from packages/@pollyjs/adapter/tests/unit/utils/human-time-to-ms-test.js
rename to packages/@pollyjs/adapter/tests/unit/utils/dehumanize-time.js
index 76ded47b..518d16cc 100644
--- a/packages/@pollyjs/adapter/tests/unit/utils/human-time-to-ms-test.js
+++ b/packages/@pollyjs/adapter/tests/unit/utils/dehumanize-time.js
@@ -1,15 +1,22 @@
-import humanTimeToMilliseconds from '../../../src/utils/human-time-to-ms';
+import dehumanizeTime from '../../../src/utils/dehumanize-time';
 
-describe('Unit | Utils | humanTimeToMilliseconds', function() {
+describe('Unit | Utils | dehumanizeTime', function() {
   it('should exist', function() {
-    expect(humanTimeToMilliseconds).to.be.a('function');
+    expect(dehumanizeTime).to.be.a('function');
   });
 
   it('should work', function() {
+    expect(dehumanizeTime(null)).to.be.NaN;
+    expect(dehumanizeTime(undefined)).to.be.NaN;
+    expect(dehumanizeTime(true)).to.be.NaN;
+    expect(dehumanizeTime(false)).to.be.NaN;
+
     [
-      [[undefined, null, ''], 0],
       [['1ms', '1millisecond', '1 milliseconds'], 1],
+      [['10ms', '10millisecond', '10 milliseconds'], 10],
+      [['100ms', '100millisecond', '100 milliseconds'], 100],
       [['1s', '1sec', '1secs', '1 second', '1 seconds'], 1000],
+      [['1.5s', '1.5sec', '1.5secs', '1.5 second', '1.5 seconds'], 1500],
       [['1m', '1min', '1mins', '1 minute', '1 minutes'], 1000 * 60],
       [['1h', '1hr', '1hrs', '1 hour', '1 hours'], 1000 * 60 * 60],
       [['1d', '1day', '1 days'], 1000 * 60 * 60 * 24],
@@ -23,9 +30,7 @@ describe('Unit | Utils | humanTimeToMilliseconds', function() {
         33005045006
       ]
     ].forEach(([inputs, value]) => {
-      inputs.forEach(str =>
-        expect(humanTimeToMilliseconds(str)).to.equal(value)
-      );
+      inputs.forEach(str => expect(dehumanizeTime(str)).to.equal(value));
     });
   });
 });