diff --git a/bindings/python/sample_arm.py b/bindings/python/sample_arm.py
index a8491d19..e910defc 100755
--- a/bindings/python/sample_arm.py
+++ b/bindings/python/sample_arm.py
@@ -85,7 +85,8 @@ def test_thumb():
         mu.hook_add(UC_HOOK_CODE, hook_code)
 
         # emulate machine code in infinite time
-        mu.emu_start(ADDRESS, ADDRESS + len(THUMB_CODE))
+        # Note we start at ADDRESS | 1 to indicate THUMB mode.
+        mu.emu_start(ADDRESS | 1, ADDRESS + len(THUMB_CODE))
 
         # now print out some registers
         print(">>> Emulation done. Below is the CPU context")
diff --git a/samples/sample_arm.c b/samples/sample_arm.c
index 2c69ce6a..fc3570ec 100644
--- a/samples/sample_arm.c
+++ b/samples/sample_arm.c
@@ -135,7 +135,8 @@ static void test_thumb(void)
 
     // emulate machine code in infinite time (last param = 0), or when
     // finishing all the code.
-    err = uc_emu_start(uc, ADDRESS, ADDRESS + sizeof(THUMB_CODE) -1, 0, 0);
+    // Note we start at ADDRESS | 1 to indicate THUMB mode.
+    err = uc_emu_start(uc, ADDRESS | 1, ADDRESS + sizeof(THUMB_CODE) -1, 0, 0);
     if (err) {
         printf("Failed on uc_emu_start() with error returned: %u\n", err);
     }