diff --git a/examples/jvm-interop/bridge.c b/examples/jvm-interop/bridge.c
index 75621e4877..0585e075c2 100644
--- a/examples/jvm-interop/bridge.c
+++ b/examples/jvm-interop/bridge.c
@@ -14,6 +14,11 @@
 
 JavaVM* vm;
 
+#define ERR_MSG_MAX_SIZE 256
+
+jmp_buf exception_buffer;
+char* err_msg[ERR_MSG_MAX_SIZE] = {0};
+
 jint JNI_OnLoad(JavaVM *loadedVM, void *reserved)
 {
     // https://docs.oracle.com/javase/8/docs/technotes/guides/jni/spec/invocation.html
@@ -37,27 +42,17 @@ void roc_dealloc(void *ptr, unsigned int alignment)
     free(ptr);
 }
 
-jint javaException(void *ptr)
-{
-    JNIEnv* env = NULL;
-    jint returnCode = (*vm)->GetEnv(vm, (void**)&env, JNI_VERSION_1_6);
-
-    if (returnCode != JNI_OK) {
-        printf("failed to get jvm env");
-        exit(1);
-    }
-
-    char* msg = ptr == NULL ? "roc panic" : (char*)ptr;
-    jclass exceptionClass = (*env)->FindClass(env, "java/lang/RuntimeException");
-    return (*env)->ThrowNew(env, exceptionClass, msg);
-}
-
 __attribute__((noreturn)) void roc_panic(void *ptr, unsigned int alignment)
 {
-    // TODO throw a RuntimeException from JNI
-    if (ptr != NULL)
-        printf("%s", ptr);
-    exit(1);
+    if (ptr != NULL) {
+        int ptr_len = strlen((char*)ptr);
+        int len = ptr_len > ERR_MSG_MAX_SIZE ? ERR_MSG_MAX_SIZE : ptr_len;
+        strncpy((char*)err_msg, ptr, (len + 1));
+    }
+    else {
+        strncpy((char *)err_msg, "roc paniced", strlen("roc paniced") + 1);
+    }
+    longjmp(exception_buffer, 1);
 }
 
 
@@ -327,6 +322,15 @@ JNIEXPORT jlong JNICALL Java_javaSource_Demo_factorial
    (JNIEnv *env, jobject thisObj, jlong n)
 {
     int64_t ret;
-    roc__programForHost_1__Factorial_caller(&n, 0, &ret);
-    return ret;
+    // can crash - meaning call roc_panic, so we set a jump here
+    if (setjmp(exception_buffer)) {
+        // exception was thrown, handle it
+        jclass exClass = (*env)->FindClass(env, "java/lang/RuntimeException");
+        const char *msg = (const char *)err_msg;
+        return (*env)->ThrowNew(env, exClass, msg);
+    }
+    else {
+        roc__programForHost_1__Factorial_caller(&n, 0, &ret);
+        return ret;
+    }
 }
diff --git a/examples/jvm-interop/javaSource/Demo.java b/examples/jvm-interop/javaSource/Demo.java
index 677dfc63df..aa233aea79 100644
--- a/examples/jvm-interop/javaSource/Demo.java
+++ b/examples/jvm-interop/javaSource/Demo.java
@@ -12,7 +12,7 @@ public class Demo {
 
    public static native int[] mulArrByScalar(int[] arr, int scalar);
 
-   public static native long factorial(long n);
+   public static native long factorial(long n) throws RuntimeException;
 
 
    public static void main(String[] args) {
@@ -23,7 +23,7 @@ public class Demo {
       // array demo
       int[] arr = {10, 20, 30, 40};
       int x = 3;
-      System.out.println("Array " + Arrays.toString(arr) +
+      System.out.println(Arrays.toString(arr) +
                          " multipled by " + x +
                          " results in " + Arrays.toString(mulArrByScalar(arr, x)) +
                          "\n");
@@ -33,7 +33,7 @@ public class Demo {
       // this will panic from the roc side if n is negative
       // and in turn will throw a JVM RuntimeException
       long n = 5;
-      System.out.println("Factorial of " + n + " is " + factorial(n) + "\n");
+      System.out.println("Factorial of " + n + " is " + factorial(n));
 
    }
 }