diff --git a/devtools/gradle/gradle-application-plugin/src/main/java/io/quarkus/gradle/QuarkusPlugin.java b/devtools/gradle/gradle-application-plugin/src/main/java/io/quarkus/gradle/QuarkusPlugin.java
index 1dc5149b41b73..1274a414b4f70 100644
--- a/devtools/gradle/gradle-application-plugin/src/main/java/io/quarkus/gradle/QuarkusPlugin.java
+++ b/devtools/gradle/gradle-application-plugin/src/main/java/io/quarkus/gradle/QuarkusPlugin.java
@@ -242,19 +242,19 @@ private void registerConditionalDependencies(Project project) {
                     Set<ExtensionDependency> implementationExtensions = conditionalDependenciesEnabler
                             .declareConditionalDependencies(JavaPlugin.IMPLEMENTATION_CONFIGURATION_NAME);
                     deploymentClasspathBuilder.createBuildClasspath(implementationExtensions,
-                            JavaPlugin.IMPLEMENTATION_CONFIGURATION_NAME, true);
+                            JavaPlugin.IMPLEMENTATION_CONFIGURATION_NAME);
                 });
         project.getConfigurations().getByName(DEV_MODE_CONFIGURATION_NAME).getIncoming().beforeResolve((devDependencies) -> {
             Set<ExtensionDependency> devModeExtensions = conditionalDependenciesEnabler
                     .declareConditionalDependencies(DEV_MODE_CONFIGURATION_NAME);
-            deploymentClasspathBuilder.createBuildClasspath(devModeExtensions, DEV_MODE_CONFIGURATION_NAME, false);
+            deploymentClasspathBuilder.createBuildClasspath(devModeExtensions, DEV_MODE_CONFIGURATION_NAME);
         });
         project.getConfigurations().getByName(JavaPlugin.TEST_COMPILE_CLASSPATH_CONFIGURATION_NAME).getIncoming()
                 .beforeResolve((testDependencies) -> {
                     Set<ExtensionDependency> testExtensions = conditionalDependenciesEnabler
                             .declareConditionalDependencies(JavaPlugin.TEST_IMPLEMENTATION_CONFIGURATION_NAME);
                     deploymentClasspathBuilder.createBuildClasspath(testExtensions,
-                            JavaPlugin.TEST_IMPLEMENTATION_CONFIGURATION_NAME, false);
+                            JavaPlugin.TEST_IMPLEMENTATION_CONFIGURATION_NAME);
                 });
     }
 
diff --git a/devtools/gradle/gradle-application-plugin/src/main/java/io/quarkus/gradle/dependency/ApplicationDeploymentClasspathBuilder.java b/devtools/gradle/gradle-application-plugin/src/main/java/io/quarkus/gradle/dependency/ApplicationDeploymentClasspathBuilder.java
index 6d9332c6d743d..45827d9fd74ec 100644
--- a/devtools/gradle/gradle-application-plugin/src/main/java/io/quarkus/gradle/dependency/ApplicationDeploymentClasspathBuilder.java
+++ b/devtools/gradle/gradle-application-plugin/src/main/java/io/quarkus/gradle/dependency/ApplicationDeploymentClasspathBuilder.java
@@ -12,7 +12,7 @@ public class ApplicationDeploymentClasspathBuilder {
     private static final String DEPLOYMENT_CONFIGURATION_SUFFIX = "Deployment";
 
     private final Project project;
-    private final Set<ExtensionDependency> commonExtensions = new HashSet<>();
+    private final Set<ExtensionDependency> alreadyProcessed = new HashSet<>();
 
     public ApplicationDeploymentClasspathBuilder(Project project) {
         this.project = project;
@@ -22,19 +22,18 @@ public static String toDeploymentConfigurationName(String baseConfigurationName)
         return baseConfigurationName + DEPLOYMENT_CONFIGURATION_SUFFIX;
     }
 
-    public void createBuildClasspath(Set<ExtensionDependency> extensions, String baseConfigurationName, boolean common) {
+    public synchronized void createBuildClasspath(Set<ExtensionDependency> extensions, String baseConfigurationName) {
         String deploymentConfigurationName = toDeploymentConfigurationName(baseConfigurationName);
         project.getConfigurations().create(deploymentConfigurationName);
 
         DependencyHandler dependencies = project.getDependencies();
         for (ExtensionDependency extension : extensions) {
-            if (common) {
-                commonExtensions.add(extension);
-            } else if (commonExtensions.contains(extension)) {
+            requireDeploymentDependency(deploymentConfigurationName, extension, dependencies);
+            if (alreadyProcessed.contains(extension)) {
                 continue;
             }
+            alreadyProcessed.add(extension);
             extension.createDeploymentVariant(dependencies);
-            requireDeploymentDependency(deploymentConfigurationName, extension, dependencies);
         }
     }