diff --git a/CHANGELOG.md b/CHANGELOG.md
index e69de29bb..0062ea300 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -0,0 +1 @@
+Correct the function BooleanExpression#then to BooleanExpression#thenElse (#1268)
diff --git a/spec/fixtures/sources/commonjs-params/index.js b/spec/fixtures/sources/commonjs-params/index.js
index 5f982fcaa..2418d32a9 100644
--- a/spec/fixtures/sources/commonjs-params/index.js
+++ b/spec/fixtures/sources/commonjs-params/index.js
@@ -4,10 +4,10 @@ const params = require("../../../../src/params");
 
 params.defineString("BORING");
 const foo = params.defineString("FOO", { input: { text: { validationRegex: "w+" } } });
-const bar = params.defineString("BAR", { default: foo , label: "asdf" });
+const bar = params.defineString("BAR", { default: foo, label: "asdf" });
 params.defineString("BAZ", { input: { select: { options: [{ value: "a" }, { value: "b" }] } } });
 
-params.defineInt("AN_INT", { default: bar.equals("qux").then(0, 1) });
+params.defineInt("AN_INT", { default: bar.equals("qux").thenElse(0, 1) });
 params.defineInt("ANOTHER_INT", {
   input: {
     select: {
diff --git a/spec/params/params.spec.ts b/spec/params/params.spec.ts
index 9148d5483..fad4f00b5 100644
--- a/spec/params/params.spec.ts
+++ b/spec/params/params.spec.ts
@@ -5,7 +5,7 @@ describe("Params spec extraction", () => {
   it("converts Expressions in the param default to strings", () => {
     const bar = params.defineInt("BAR");
     expect(
-      params.defineString("FOO", { default: bar.notEquals(22).then("asdf", "jkl;") }).toSpec()
+      params.defineString("FOO", { default: bar.notEquals(22).thenElse("asdf", "jkl;") }).toSpec()
         .default
     ).to.equal(`{{ params.BAR != 22 ? "asdf" : "jkl;" }}`);
   });
@@ -174,13 +174,13 @@ describe("Params value extraction", () => {
 
   it("can select the output of a ternary expression based on the comparison", () => {
     const trueExpr = params.defineString("A_STRING").equals(params.defineString("SAME_STRING"));
-    expect(trueExpr.then(1, 0).value()).to.equal(1);
+    expect(trueExpr.thenElse(1, 0).value()).to.equal(1);
     const falseExpr = params.defineInt("AN_INT").equals(params.defineInt("DIFF_INT"));
-    expect(falseExpr.then(1, 0).value()).to.equal(0);
+    expect(falseExpr.thenElse(1, 0).value()).to.equal(0);
 
     const twentytwo = params.defineInt("DIFF_INT");
-    expect(trueExpr.then(twentytwo, 0).value()).to.equal(22);
-    expect(falseExpr.then(1, twentytwo).value()).to.equal(22);
+    expect(trueExpr.thenElse(twentytwo, 0).value()).to.equal(22);
+    expect(falseExpr.thenElse(1, twentytwo).value()).to.equal(22);
   });
 });
 
@@ -280,13 +280,15 @@ describe("Params as CEL", () => {
     expect(
       booleanExpr.then(params.defineString("FOO"), params.defineString("BAR")).toCEL()
     ).to.equal("{{ params.BOOL ? params.FOO : params.BAR }}");
-    expect(cmpExpr.then("asdf", "jkl;").toCEL()).to.equal(
+    expect(cmpExpr.thenElse("asdf", "jkl;").toCEL()).to.equal(
       '{{ params.A != params.B ? "asdf" : "jkl;" }}'
     );
-    expect(cmpExpr.then(-11, 22).toCEL()).to.equal("{{ params.A != params.B ? -11 : 22 }}");
-    expect(cmpExpr.then(false, true).toCEL()).to.equal("{{ params.A != params.B ? false : true }}");
-    expect(cmpExpr.then(params.defineString("FOO"), params.defineString("BAR")).toCEL()).to.equal(
-      "{{ params.A != params.B ? params.FOO : params.BAR }}"
+    expect(cmpExpr.thenElse(-11, 22).toCEL()).to.equal("{{ params.A != params.B ? -11 : 22 }}");
+    expect(cmpExpr.thenElse(false, true).toCEL()).to.equal(
+      "{{ params.A != params.B ? false : true }}"
     );
+    expect(
+      cmpExpr.thenElse(params.defineString("FOO"), params.defineString("BAR")).toCEL()
+    ).to.equal("{{ params.A != params.B ? params.FOO : params.BAR }}");
   });
 });
diff --git a/spec/runtime/manifest.spec.ts b/spec/runtime/manifest.spec.ts
index e124f6190..22c5f8af1 100644
--- a/spec/runtime/manifest.spec.ts
+++ b/spec/runtime/manifest.spec.ts
@@ -127,14 +127,14 @@ describe("stackToWire", () => {
           labels: {},
           httpsTrigger: {},
           concurrency: intParam,
-          maxInstances: intParam.equals(24).then(-1, 1),
+          maxInstances: intParam.equals(24).thenElse(-1, 1),
         },
         v2schedule: {
           platform: "gcfv2",
           entryPoint: "v2callable",
           labels: {},
           scheduleTrigger: {
-            schedule: stringParam.equals("America/Mexico_City").then("mexico", "usa"),
+            schedule: stringParam.equals("America/Mexico_City").thenElse("mexico", "usa"),
             timeZone: stringParam,
           },
         },
diff --git a/src/params/types.ts b/src/params/types.ts
index fccdcbf86..7dd9b99bc 100644
--- a/src/params/types.ts
+++ b/src/params/types.ts
@@ -145,7 +145,7 @@ export class CompareExpression<
   }
 
   /** Returns a TernaryExpression which can resolve to one of two values, based on the resolution of this comparison. */
-  then<retT extends string | number | boolean | string[]>(
+  thenElse<retT extends string | number | boolean | string[]>(
     ifTrue: retT | Expression<retT>,
     ifFalse: retT | Expression<retT>
   ) {