diff --git a/loan-agreement/src/main/java/de/weinbrecht/luc/bpm/architecture/loan/agreement/adapter/in/web/RestExceptionHandlerAdvice.java b/loan-agreement/src/main/java/de/weinbrecht/luc/bpm/architecture/loan/agreement/adapter/in/web/RestExceptionHandlerAdvice.java
new file mode 100644
index 0000000..968a814
--- /dev/null
+++ b/loan-agreement/src/main/java/de/weinbrecht/luc/bpm/architecture/loan/agreement/adapter/in/web/RestExceptionHandlerAdvice.java
@@ -0,0 +1,27 @@
+package de.weinbrecht.luc.bpm.architecture.loan.agreement.adapter.in.web;
+
+import de.weinbrecht.luc.bpm.architecture.loan.agreement.domain.service.LoanAgreementException;
+import io.github.domainprimitives.validation.InvariantException;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.ControllerAdvice;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.context.request.WebRequest;
+import org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler;
+
+import static org.springframework.http.HttpStatus.BAD_REQUEST;
+import static org.springframework.http.HttpStatus.INTERNAL_SERVER_ERROR;
+
+@ControllerAdvice
+public class RestExceptionHandlerAdvice extends ResponseEntityExceptionHandler {
+
+    @ExceptionHandler(value = LoanAgreementException.class)
+    protected ResponseEntity<Object> handleDomainException(LoanAgreementException ex, WebRequest request) {
+        return handleExceptionInternal(ex, ex.getMessage(), new HttpHeaders(), INTERNAL_SERVER_ERROR, request);
+    }
+
+    @ExceptionHandler(value = InvariantException.class)
+    protected ResponseEntity<Object> handleInvariantConflict(InvariantException ex, WebRequest request) {
+        return handleExceptionInternal(ex, ex.getMessage(), new HttpHeaders(), BAD_REQUEST, request);
+    }
+}
diff --git a/loan-agreement/src/main/java/de/weinbrecht/luc/bpm/architecture/loan/agreement/domain/service/LoanAgreementException.java b/loan-agreement/src/main/java/de/weinbrecht/luc/bpm/architecture/loan/agreement/domain/service/LoanAgreementException.java
index 1e2104c..03fec6a 100644
--- a/loan-agreement/src/main/java/de/weinbrecht/luc/bpm/architecture/loan/agreement/domain/service/LoanAgreementException.java
+++ b/loan-agreement/src/main/java/de/weinbrecht/luc/bpm/architecture/loan/agreement/domain/service/LoanAgreementException.java
@@ -2,10 +2,6 @@ package de.weinbrecht.luc.bpm.architecture.loan.agreement.domain.service;
 
 public class LoanAgreementException extends RuntimeException {
 
-    public LoanAgreementException(String message) {
-        super(message);
-    }
-
     public LoanAgreementException(String message, Throwable cause) {
         super(message, cause);
     }
diff --git a/loan-agreement/src/test/java/de/weinbrecht/luc/bpm/architecture/loan/agreement/adapter/in/web/DemoController.java b/loan-agreement/src/test/java/de/weinbrecht/luc/bpm/architecture/loan/agreement/adapter/in/web/DemoController.java
new file mode 100644
index 0000000..c88c6ae
--- /dev/null
+++ b/loan-agreement/src/test/java/de/weinbrecht/luc/bpm/architecture/loan/agreement/adapter/in/web/DemoController.java
@@ -0,0 +1,24 @@
+package de.weinbrecht.luc.bpm.architecture.loan.agreement.adapter.in.web;
+
+import de.weinbrecht.luc.bpm.architecture.loan.agreement.domain.service.LoanAgreementException;
+import io.github.domainprimitives.validation.InvariantException;
+import lombok.RequiredArgsConstructor;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RequiredArgsConstructor
+@RestController
+@RequestMapping("error")
+public class DemoController {
+
+    @GetMapping("/invariant")
+    public void provideInvariant() {
+        throw new InvariantException("Foo", "Testing");
+    }
+
+    @GetMapping("/domain")
+    public void provideDomainException() {
+        throw new LoanAgreementException("Bar", null);
+    }
+}
diff --git a/loan-agreement/src/test/java/de/weinbrecht/luc/bpm/architecture/loan/agreement/adapter/in/web/RestExceptionHandlerAdviceTest.java b/loan-agreement/src/test/java/de/weinbrecht/luc/bpm/architecture/loan/agreement/adapter/in/web/RestExceptionHandlerAdviceTest.java
new file mode 100644
index 0000000..d2148cc
--- /dev/null
+++ b/loan-agreement/src/test/java/de/weinbrecht/luc/bpm/architecture/loan/agreement/adapter/in/web/RestExceptionHandlerAdviceTest.java
@@ -0,0 +1,27 @@
+package de.weinbrecht.luc.bpm.architecture.loan.agreement.adapter.in.web;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest;
+import org.springframework.test.web.servlet.MockMvc;
+
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+
+@WebMvcTest(DemoController.class)
+class RestExceptionHandlerAdviceTest {
+
+    @Autowired
+    private MockMvc mockMvc;
+
+    @Test
+    void should_handle_invariants() throws Exception {
+        mockMvc.perform(get("/error/invariant")).andExpect(status().isBadRequest());
+    }
+
+    @Test
+    void should_handle_domain_exception() throws Exception {
+        mockMvc.perform(get("/error/domain")).andExpect(status().isInternalServerError());
+    }
+}
\ No newline at end of file
diff --git a/loan-agreement/src/test/java/de/weinbrecht/luc/bpm/architecture/loan/agreement/domain/service/LoanAgreementServiceTest.java b/loan-agreement/src/test/java/de/weinbrecht/luc/bpm/architecture/loan/agreement/domain/service/LoanAgreementServiceTest.java
index 948417b..b2c6668 100644
--- a/loan-agreement/src/test/java/de/weinbrecht/luc/bpm/architecture/loan/agreement/domain/service/LoanAgreementServiceTest.java
+++ b/loan-agreement/src/test/java/de/weinbrecht/luc/bpm/architecture/loan/agreement/domain/service/LoanAgreementServiceTest.java
@@ -56,7 +56,7 @@ class LoanAgreementServiceTest {
         assertThrows(LoanAgreementException.class,
                 () -> classUnderTest.create(loanAgreement, caseId));
 
-        verify(recommendationTrigger, never()).startLoanAgreement(caseId, any());
+        verify(recommendationTrigger, never()).startLoanAgreement(eq(caseId), any());
     }
 
     @Test
diff --git a/recommendation/src/main/java/de/weinbrecht/luc/bpm/architecture/recommendation/adapter/in/web/RestExceptionHandlerAdvice.java b/recommendation/src/main/java/de/weinbrecht/luc/bpm/architecture/recommendation/adapter/in/web/RestExceptionHandlerAdvice.java
new file mode 100644
index 0000000..eed729f
--- /dev/null
+++ b/recommendation/src/main/java/de/weinbrecht/luc/bpm/architecture/recommendation/adapter/in/web/RestExceptionHandlerAdvice.java
@@ -0,0 +1,20 @@
+package de.weinbrecht.luc.bpm.architecture.recommendation.adapter.in.web;
+
+import io.github.domainprimitives.validation.InvariantException;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.ControllerAdvice;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.context.request.WebRequest;
+import org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler;
+
+import static org.springframework.http.HttpStatus.BAD_REQUEST;
+
+@ControllerAdvice
+public class RestExceptionHandlerAdvice extends ResponseEntityExceptionHandler {
+
+    @ExceptionHandler(value = InvariantException.class)
+    protected ResponseEntity<Object> handleInvariantConflict(InvariantException ex, WebRequest request) {
+        return handleExceptionInternal(ex, ex.getMessage(), new HttpHeaders(), BAD_REQUEST, request);
+    }
+}
diff --git a/recommendation/src/test/java/de/weinbrecht/luc/bpm/architecture/recommendation/adapter/in/web/DemoController.java b/recommendation/src/test/java/de/weinbrecht/luc/bpm/architecture/recommendation/adapter/in/web/DemoController.java
new file mode 100644
index 0000000..86aef03
--- /dev/null
+++ b/recommendation/src/test/java/de/weinbrecht/luc/bpm/architecture/recommendation/adapter/in/web/DemoController.java
@@ -0,0 +1,18 @@
+package de.weinbrecht.luc.bpm.architecture.recommendation.adapter.in.web;
+
+import io.github.domainprimitives.validation.InvariantException;
+import lombok.RequiredArgsConstructor;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RequiredArgsConstructor
+@RestController
+@RequestMapping("error")
+public class DemoController {
+
+    @GetMapping()
+    public void provideInvariant() {
+        throw new InvariantException("Foo", "Testing");
+    }
+}
diff --git a/recommendation/src/test/java/de/weinbrecht/luc/bpm/architecture/recommendation/adapter/in/web/RestExceptionHandlerAdviceTest.java b/recommendation/src/test/java/de/weinbrecht/luc/bpm/architecture/recommendation/adapter/in/web/RestExceptionHandlerAdviceTest.java
new file mode 100644
index 0000000..dbf3b2f
--- /dev/null
+++ b/recommendation/src/test/java/de/weinbrecht/luc/bpm/architecture/recommendation/adapter/in/web/RestExceptionHandlerAdviceTest.java
@@ -0,0 +1,22 @@
+package de.weinbrecht.luc.bpm.architecture.recommendation.adapter.in.web;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest;
+import org.springframework.test.web.servlet.MockMvc;
+
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+
+@WebMvcTest(DemoController.class)
+class RestExceptionHandlerAdviceTest {
+
+    @Autowired
+    private MockMvc mockMvc;
+
+    @Test
+    void should_handle_invariants() throws Exception {
+        mockMvc.perform(get("/error")).andExpect(status().isBadRequest());
+    }
+}
\ No newline at end of file