diff --git a/ceno_emul/src/rv32im.rs b/ceno_emul/src/rv32im.rs
index 0e69877e8..e50c184dc 100644
--- a/ceno_emul/src/rv32im.rs
+++ b/ceno_emul/src/rv32im.rs
@@ -91,7 +91,7 @@ pub enum TrapCause {
     LoadAccessFault(ByteAddr),
     StoreAddressMisaligned(ByteAddr),
     StoreAccessFault,
-    EnvironmentCallFromUserMode,
+    EcallError,
 }
 
 #[derive(Clone, Debug, Default)]
diff --git a/ceno_emul/src/vm_state.rs b/ceno_emul/src/vm_state.rs
index 6bccfc035..92d0b33a4 100644
--- a/ceno_emul/src/vm_state.rs
+++ b/ceno_emul/src/vm_state.rs
@@ -90,7 +90,7 @@ impl EmuContext for VMState {
             self.succeeded = true;
             Ok(true)
         } else {
-            self.trap(TrapCause::EnvironmentCallFromUserMode)
+            self.trap(TrapCause::EcallError)
         }
     }
 
diff --git a/ceno_emul/tests/data/README.md b/ceno_emul/tests/data/README.md
index e71cf5728..746886507 100644
--- a/ceno_emul/tests/data/README.md
+++ b/ceno_emul/tests/data/README.md
@@ -3,5 +3,5 @@
 ```bash
 cd ceno_rt
 cargo build --release --examples
-cp ../target/riscv32im-unknown-none-elf/release/examples/ceno_rt_mini ../ceno_emul/tests/data/
+cp ../target/riscv32im-unknown-none-elf/release/examples/ceno_rt_{mini,panic,mem} ../ceno_emul/tests/data/
 ```
\ No newline at end of file
diff --git a/ceno_emul/tests/data/ceno_rt_panic b/ceno_emul/tests/data/ceno_rt_panic
new file mode 100755
index 000000000..927fa7df0
Binary files /dev/null and b/ceno_emul/tests/data/ceno_rt_panic differ
diff --git a/ceno_emul/tests/test_elf.rs b/ceno_emul/tests/test_elf.rs
index e3e548e76..9e0f516d3 100644
--- a/ceno_emul/tests/test_elf.rs
+++ b/ceno_emul/tests/test_elf.rs
@@ -19,6 +19,25 @@ fn test_ceno_rt_mini() -> Result<()> {
     Ok(())
 }
 
+#[test]
+fn test_ceno_rt_panic() -> Result<()> {
+    let mut state = VMState::new(CENO_PLATFORM);
+
+    // Load an ELF program in memory.
+    let program_elf = include_bytes!("./data/ceno_rt_panic");
+    let program = Program::load_elf(program_elf, u32::MAX)?;
+    for (addr, word) in program.image.iter() {
+        let addr = ByteAddr(*addr).waddr();
+        state.init_memory(addr, *word);
+    }
+    assert_eq!(program.entry, CENO_PLATFORM.pc_start());
+
+    let res = run(&mut state);
+    assert!(matches!(res, Err(e) if e.to_string().contains("EcallError")));
+
+    Ok(())
+}
+
 #[test]
 fn test_ceno_rt_mem() -> Result<()> {
     let mut state = VMState::new(CENO_PLATFORM);
diff --git a/ceno_rt/examples/ceno_rt_panic.rs b/ceno_rt/examples/ceno_rt_panic.rs
new file mode 100644
index 000000000..24a0b20b4
--- /dev/null
+++ b/ceno_rt/examples/ceno_rt_panic.rs
@@ -0,0 +1,10 @@
+#![no_main]
+#![no_std]
+
+#[allow(unused_imports)]
+use ceno_rt;
+
+#[no_mangle]
+fn main() {
+    panic!("This is a panic message!");
+}