diff --git a/.github/workflows/continuous-integration.yml b/.github/workflows/continuous-integration.yml
index d274c3d351..109d4b1071 100644
--- a/.github/workflows/continuous-integration.yml
+++ b/.github/workflows/continuous-integration.yml
@@ -26,13 +26,33 @@ jobs:
         with:
           website: jdk.java.net
           release: 27
-      - name: 'Set up Default JDK'
+      # Use Zulu for JDK 17 on Windows, as Temurin build of 17.0.19 is still not released
+      - name: 'Set up Zulu JDK 17 on Windows'
         uses: actions/setup-java@v5
         with:
-          java-version: 25
+          java-version: 17
+          distribution: 'zulu'
+          check-latest: 'true'
+        if: runner.os == 'Windows'
+      - name: 'Set up Temurin JDK 17'
+        uses: actions/setup-java@v5
+        with:
+          java-version: 17
+          distribution: 'temurin'
+          check-latest: 'true'
+        if: runner.os != 'Windows'
+      - name: 'Set up JDKs'
+        uses: actions/setup-java@v5
+        with:
+          java-version: |
+            21
+            25
           distribution: 'temurin'
+          check-latest: 'true'
       - name: Setup Gradle
         uses: gradle/actions/setup-gradle@v5
+      - name: List toolchains
+        run: ./gradlew javaToolchains
       - name: Build and test
         run: ./gradlew build
       - name: Run shellcheck
diff --git a/guava-recent-unit-tests/src/test/java/com/uber/nullaway/guava/NullAwayGuavaParametricNullnessTests.java b/guava-recent-unit-tests/src/test/java/com/uber/nullaway/guava/NullAwayGuavaParametricNullnessTests.java
index 9bb43bb93b..d4e52d3926 100644
--- a/guava-recent-unit-tests/src/test/java/com/uber/nullaway/guava/NullAwayGuavaParametricNullnessTests.java
+++ b/guava-recent-unit-tests/src/test/java/com/uber/nullaway/guava/NullAwayGuavaParametricNullnessTests.java
@@ -26,7 +26,6 @@
 import com.uber.nullaway.generics.JSpecifyJavacConfig;
 import java.util.Arrays;
 import java.util.List;
-import org.junit.Assume;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
@@ -86,8 +85,6 @@ public void testFutureCallbackParametricNullness() {
 
   @Test
   public void jspecifyFutureCallback() {
-    // to ensure javac reads proper generic types from the Guava jar
-    Assume.assumeTrue(Runtime.version().feature() >= 21);
     jspecifyCompilationHelper
         .addSourceLines(
             "Test.java",
@@ -134,8 +131,6 @@ public void testIterableParametricNullness() {
 
   @Test
   public void jspecifyIterables() {
-    // to ensure javac reads proper generic types from the Guava jar
-    Assume.assumeTrue(Runtime.version().feature() >= 21);
     jspecifyCompilationHelper
         .addSourceLines(
             "Test.java",
@@ -164,8 +159,6 @@ public void jspecifyIterables() {
 
   @Test
   public void jspecifyComparators() {
-    // to ensure javac reads proper generic types from the Guava jar
-    Assume.assumeTrue(Runtime.version().feature() >= 21);
     jspecifyCompilationHelper
         .addSourceLines(
             "Test.java",
@@ -246,8 +239,6 @@ public void testFunctionMethodOverride() {
 
   @Test
   public void newHashSetPassingNullable() {
-    // to ensure javac reads proper generic types from the Guava jar
-    Assume.assumeTrue(Runtime.version().feature() >= 21);
     jspecifyCompilationHelper
         .addSourceLines(
             "Test.java",
diff --git a/nullaway/src/test/java/com/uber/nullaway/jspecify/BytecodeGenericsTests.java b/nullaway/src/test/java/com/uber/nullaway/jspecify/BytecodeGenericsTests.java
index 913783e7d9..62558893e5 100644
--- a/nullaway/src/test/java/com/uber/nullaway/jspecify/BytecodeGenericsTests.java
+++ b/nullaway/src/test/java/com/uber/nullaway/jspecify/BytecodeGenericsTests.java
@@ -4,7 +4,6 @@
 import com.uber.nullaway.NullAwayTestsBase;
 import com.uber.nullaway.generics.JSpecifyJavacConfig;
 import java.util.List;
-import org.junit.Assume;
 import org.junit.Test;
 
 public class BytecodeGenericsTests extends NullAwayTestsBase {
@@ -83,8 +82,6 @@ static void testNegative(NullableTypeParam<@Nullable String> t1) {
 
   @Test
   public void genericsChecksForFieldAssignments() {
-    // to read annotations properly from bytecode
-    Assume.assumeTrue(Runtime.version().feature() >= 21);
     makeHelper()
         .addSourceLines(
             "Test.java",
@@ -110,9 +107,6 @@ static void testNegative(NullableTypeParam<@Nullable String> t1) {
 
   @Test
   public void genericsChecksForParamPassingAndReturns() {
-    // to read annotations properly from bytecode
-    Assume.assumeTrue(Runtime.version().feature() >= 21);
-
     makeHelper()
         .addSourceLines(
             "Test.java",
@@ -245,8 +239,6 @@ static void useTestFunc(String s) {
 
   @Test
   public void callMethodTakingJavaUtilFunction() {
-    // to read annotations properly from bytecode
-    Assume.assumeTrue(Runtime.version().feature() >= 21);
     makeHelper()
         .addSourceLines(
             "Test.java",