diff --git a/packages/workbox-range-requests/src/utils/calculateEffectiveBoundaries.ts b/packages/workbox-range-requests/src/utils/calculateEffectiveBoundaries.ts
index b4c1af86f..75ee07f1f 100644
--- a/packages/workbox-range-requests/src/utils/calculateEffectiveBoundaries.ts
+++ b/packages/workbox-range-requests/src/utils/calculateEffectiveBoundaries.ts
@@ -44,14 +44,14 @@ function calculateEffectiveBoundaries(
   let effectiveStart: number;
   let effectiveEnd: number;
 
-  if (start && end) {
+  if (start !== undefined && end !== undefined) {
     effectiveStart = start;
     // Range values are inclusive, so add 1 to the value.
     effectiveEnd = end + 1;
-  } else if (start && !end) {
+  } else if (start !== undefined && end === undefined) {
     effectiveStart = start;
     effectiveEnd = blobSize;
-  } else if (end && !start) {
+  } else if (end !== undefined && start === undefined) {
     effectiveStart = blobSize - end;
     effectiveEnd = blobSize;
   }
diff --git a/test/workbox-range-requests/sw/test-createPartialResponse.mjs b/test/workbox-range-requests/sw/test-createPartialResponse.mjs
index 32c56986d..b3fdbb5ab 100644
--- a/test/workbox-range-requests/sw/test-createPartialResponse.mjs
+++ b/test/workbox-range-requests/sw/test-createPartialResponse.mjs
@@ -30,10 +30,8 @@ describe(`createPartialResponse()`, function() {
       },
     });
 
-    const VALID_RESPONSE = new Response(SOURCE_BLOB);
-
     it(`should return a Response with status 416 when the 'request' parameter isn't valid`, async function() {
-      const response = await createPartialResponse(null, VALID_RESPONSE);
+      const response = await createPartialResponse(null, new Response(SOURCE_BLOB));
       expect(response.status).to.equal(416);
     });
 
@@ -44,12 +42,12 @@ describe(`createPartialResponse()`, function() {
 
     it(`should return a Response with status 416 when there's no Range: header in the request`, async function() {
       const noRangeHeaderRequest = new Request('/');
-      const response = await createPartialResponse(noRangeHeaderRequest, VALID_RESPONSE);
+      const response = await createPartialResponse(noRangeHeaderRequest, new Response(SOURCE_BLOB));
       expect(response.status).to.equal(416);
     });
 
     it(`should return the expected Response when it's called with valid parameters`, async function() {
-      const response = await createPartialResponse(VALID_REQUEST, VALID_RESPONSE);
+      const response = await createPartialResponse(VALID_REQUEST, new Response(SOURCE_BLOB));
       expect(response.status).to.equal(206);
       expect(response.headers.get('Content-Length')).to.equal('101');
       expect(response.headers.get('Content-Range')).to.equal(`bytes 100-200/${SOURCE_BLOB_SIZE}`);
@@ -61,6 +59,24 @@ describe(`createPartialResponse()`, function() {
           .to.equal(await (new Response(expectedBlob)).text());
     });
 
+    it(`should return the full body when it's called with bytes=0-`, async function() {
+      const fullBodyRequest = new Request('/', {
+        headers: {
+          range: 'bytes=0-',
+        },
+      });
+      const response = await createPartialResponse(fullBodyRequest, new Response(SOURCE_BLOB));
+      expect(response.status).to.equal(206);
+      expect(response.headers.get('Content-Length')).to.equal(`${SOURCE_BLOB_SIZE}`);
+      expect(response.headers.get('Content-Range')).to.equal(`bytes 0-${SOURCE_BLOB_SIZE - 1}/${SOURCE_BLOB_SIZE}`);
+
+      const responseBlob = await response.blob();
+      const expectedBlob = constructBlob(SOURCE_BLOB_SIZE);
+
+      expect(await (new Response(responseBlob)).text())
+          .to.equal(await (new Response(expectedBlob)).text());
+    });
+
     it(`should handle being passed a Response with a status of 206 by returning it as-is`, async function() {
       const originalPartialResponse = new Response('expected text', {status: 206});
       const createdPartialResponse = await createPartialResponse(VALID_REQUEST, originalPartialResponse);
diff --git a/test/workbox-range-requests/sw/utils/test-calculateEffectiveBoundaries.mjs b/test/workbox-range-requests/sw/utils/test-calculateEffectiveBoundaries.mjs
index 1804a1ceb..773fd29e3 100644
--- a/test/workbox-range-requests/sw/utils/test-calculateEffectiveBoundaries.mjs
+++ b/test/workbox-range-requests/sw/utils/test-calculateEffectiveBoundaries.mjs
@@ -57,8 +57,8 @@ describe(`calculateEffectiveBoundaries()`, function() {
   it(`should return the expected boundaries when it's called with valid parameters`, function() {
     const testCases = [
       [{start: 100, end: 200}, {start: 100, end: 201}],
-      [{start: null, end: 200}, {start: 56, end: 256}],
-      [{start: 100, end: null}, {start: 100, end: 256}],
+      [{start: undefined, end: 200}, {start: 56, end: 256}],
+      [{start: 100, end: undefined}, {start: 100, end: 256}],
     ];
 
     for (const [sourceBoundaries, expectedBoundaries] of testCases) {