diff --git a/scary.c b/scary.c
index 1e19a2c..06801c8 100644
--- a/scary.c
+++ b/scary.c
@@ -113,3 +113,12 @@ void scary_pop(void *p)
     Scary *ary = get(p);
     ary->length--; // do not shrink for speed
 }
+
+void *scary_dup(void *p)
+{
+    Scary *ary = get(p);
+    Scary *dup = xmalloc(sizeof(Scary) + ary->capacity);
+    *dup = *ary;
+    memcpy(dup->space, ary->space, ary->capacity);
+    return opaque(dup);
+}
diff --git a/scary.h b/scary.h
index 3244766..fdf74cb 100644
--- a/scary.h
+++ b/scary.h
@@ -41,5 +41,6 @@ void scary_push_uint32(void *, uint32_t);
 void scary_push_uint64(void *, uint64_t);
 void scary_push_ptr(void *, const void *);
 void scary_pop(void *ary);
+void *scary_dup(void *ary);
 
 #endif
diff --git a/testlib.c b/testlib.c
index 9d3858f..1ccccba 100644
--- a/testlib.c
+++ b/testlib.c
@@ -52,3 +52,16 @@ Test(libscary, pop) {
     cr_expect(eq(sz, 1, scary_length(a)));
     scary_free(a);
 }
+
+Test(libscary, dup) {
+    int *a = scary_new(sizeof(int));
+    scary_push(&a, 42);
+    scary_push(&a, -42);
+    int *b = scary_dup(a);
+    cr_expect(ne(ptr, a, b));
+    cr_expect(eq(sz, scary_length(a), scary_length(b)));
+    cr_expect(eq(sz, 2, scary_length(b)));
+    cr_expect(eq(int[2], a, b));
+    scary_free(b);
+    scary_free(a);
+}