diff --git a/sources/test/init-scripts/src/test/groovy/com/gradle/gradlebuildaction/BaseInitScriptTest.groovy b/sources/test/init-scripts/src/test/groovy/com/gradle/gradlebuildaction/BaseInitScriptTest.groovy
index 7b19f888..d3d94352 100644
--- a/sources/test/init-scripts/src/test/groovy/com/gradle/gradlebuildaction/BaseInitScriptTest.groovy
+++ b/sources/test/init-scripts/src/test/groovy/com/gradle/gradlebuildaction/BaseInitScriptTest.groovy
@@ -19,7 +19,6 @@ class BaseInitScriptTest extends Specification {
     static final String DEVELOCITY_PLUGIN_VERSION = '4.3'
     static final String CCUD_PLUGIN_VERSION = '2.1'
 
-    static final TestGradleVersion GRADLE_3_X = new TestGradleVersion(GradleVersion.version('3.5.1'), 7, 9)
     static final TestGradleVersion GRADLE_4_X = new TestGradleVersion(GradleVersion.version('4.10.3'), 7, 10)
     static final TestGradleVersion GRADLE_5_X = new TestGradleVersion(GradleVersion.version('5.6.4'), 8, 12)
     static final TestGradleVersion GRADLE_6_0 = new TestGradleVersion(GradleVersion.version('6.0.1'), 8, 13)
@@ -30,8 +29,7 @@ class BaseInitScriptTest extends Specification {
     static final TestGradleVersion GRADLE_8_X = new TestGradleVersion(GradleVersion.version('8.14.2'), 8, 23)
 
     static final List<TestGradleVersion> ALL_VERSIONS = [
-        GRADLE_3_X, // First version where TestKit supports environment variables
-        GRADLE_4_X,
+        GRADLE_4_X, // tooling API 9.X requires Gradle > 4 (https://docs.gradle.org/current/userguide/tooling_api.html#sec:embedding_compatibility)
         GRADLE_5_X,
         GRADLE_6_0,
         GRADLE_6_X,
@@ -42,7 +40,7 @@ class BaseInitScriptTest extends Specification {
     ]
 
     static final List<TestGradleVersion> PROJECT_PLUGIN_VERSIONS =
-        [GRADLE_3_X, GRADLE_4_X, GRADLE_5_X]
+        [GRADLE_4_X, GRADLE_5_X]
 
     static final List<TestGradleVersion> CONFIGURATION_CACHE_VERSIONS =
         [GRADLE_7_X, GRADLE_8_0, GRADLE_8_X]
diff --git a/sources/test/init-scripts/src/test/groovy/com/gradle/gradlebuildaction/TestDependencyGraph.groovy b/sources/test/init-scripts/src/test/groovy/com/gradle/gradlebuildaction/TestDependencyGraph.groovy
index 8bd3324e..0e1cfcb9 100644
--- a/sources/test/init-scripts/src/test/groovy/com/gradle/gradlebuildaction/TestDependencyGraph.groovy
+++ b/sources/test/init-scripts/src/test/groovy/com/gradle/gradlebuildaction/TestDependencyGraph.groovy
@@ -10,7 +10,7 @@ class TestDependencyGraph extends BaseInitScriptTest {
     static final TestGradleVersion GRADLE_5_1 = new TestGradleVersion(GradleVersion.version('5.1.1'), 8, 12)
     static final TestGradleVersion GRADLE_7_0 = new TestGradleVersion(GradleVersion.version('7.0.1'), 8, 12)
 
-    static final List<TestGradleVersion> NO_DEPENDENCY_GRAPH_VERSIONS = [GRADLE_3_X, GRADLE_4_X, GRADLE_5_1, GRADLE_7_0]
+    static final List<TestGradleVersion> NO_DEPENDENCY_GRAPH_VERSIONS = [GRADLE_4_X, GRADLE_5_1, GRADLE_7_0]
     static final List<TestGradleVersion> DEPENDENCY_GRAPH_VERSIONS = ALL_VERSIONS - NO_DEPENDENCY_GRAPH_VERSIONS
 
     def "does not produce dependency graph when not enabled"() {
diff --git a/sources/test/init-scripts/src/test/groovy/com/gradle/gradlebuildaction/TestDevelocityInjection.groovy b/sources/test/init-scripts/src/test/groovy/com/gradle/gradlebuildaction/TestDevelocityInjection.groovy
index 8f5c2c7c..caf3e433 100644
--- a/sources/test/init-scripts/src/test/groovy/com/gradle/gradlebuildaction/TestDevelocityInjection.groovy
+++ b/sources/test/init-scripts/src/test/groovy/com/gradle/gradlebuildaction/TestDevelocityInjection.groovy
@@ -7,7 +7,7 @@ import spock.lang.Requires
 import static org.junit.Assume.assumeTrue
 
 class TestDevelocityInjection extends BaseInitScriptTest {
-    static final List<TestGradleVersion> CCUD_COMPATIBLE_VERSIONS = ALL_VERSIONS - [GRADLE_3_X]
+    static final List<TestGradleVersion> CCUD_COMPATIBLE_VERSIONS = ALL_VERSIONS
 
     def initScript = 'gradle-actions.inject-develocity.init.gradle'