diff --git a/src/unicode.c b/src/unicode.c
index c5a971f..368dd7d 100644
--- a/src/unicode.c
+++ b/src/unicode.c
@@ -387,4 +387,23 @@ uint32_t *u32_strnrstr(const uint32_t *s1, const uint32_t *s2, const size_t s2_l
 }
 
 
+
+void u32_insert_space_at(uint32_t **s, const size_t idx, const size_t n)
+{
+    if (s == NULL || n == 0) {
+        return;
+    }
+
+    size_t len = u32_strlen(*s);
+    size_t x = idx;
+    if (idx > len) {
+        x = len;
+    }
+
+    *s = (uint32_t *) realloc(*s, (len + 1 + n) * sizeof(uint32_t));
+    u32_move(*s + x + n, *s + x, len - x);
+    u32_set(*s + x, char_space, n);
+}
+
+
 /* vim: set cindent sw=4: */
diff --git a/src/unicode.h b/src/unicode.h
index 3dcd9c8..4125b3f 100644
--- a/src/unicode.h
+++ b/src/unicode.h
@@ -248,6 +248,15 @@ uint32_t *u32_nspaces(const size_t n);
 uint32_t *u32_strnrstr(const uint32_t *s1, const uint32_t *s2, const size_t s2_len, int skip);
 
 
+/**
+ * Insert `n` spaces at position `idx` into `s`. This modifies the given string.
+ * @param s the string to modify
+ * @param idx the position at which to insert. The character previously at this position will move to the right.
+ * @param n the number of spaces to insert
+ */
+void u32_insert_space_at(uint32_t **s, const size_t idx, const size_t n);
+
+
 #endif
 
 /* vim: set cindent sw=4: */
diff --git a/utest/main.c b/utest/main.c
index 1277731..b7871ce 100644
--- a/utest/main.c
+++ b/utest/main.c
@@ -116,7 +116,8 @@ int main(void)
         cmocka_unit_test(test_is_allowed_in_shape),
         cmocka_unit_test(test_is_allowed_in_filename),
         cmocka_unit_test(test_is_allowed_in_kv_string),
-        cmocka_unit_test(test_u32_strnrstr)
+        cmocka_unit_test(test_u32_strnrstr),
+        cmocka_unit_test(test_u32_insert_space_at)
     };
 
     const struct CMUnitTest bxstring_tests[] = {
diff --git a/utest/unicode_test.c b/utest/unicode_test.c
index f0156f6..d8d13a3 100644
--- a/utest/unicode_test.c
+++ b/utest/unicode_test.c
@@ -26,6 +26,7 @@
 #include <cmocka.h>
 #include <stdio.h>
 #include <string.h>
+#include <unistr.h>
 
 #include "boxes.h"
 #include "tools.h"
@@ -183,4 +184,26 @@ void test_u32_strnrstr(void **state)
 }
 
 
+
+void test_u32_insert_space_at(void **state)
+{
+    UNUSED(state);
+
+    uint32_t *expected = u32_strconv_from_arg("x xxx  ", "ASCII");
+    assert_non_null(expected);
+    uint32_t *s = u32_strconv_from_arg("xxxx", "ASCII");
+    assert_non_null(s);
+
+    u32_insert_space_at(NULL, 2, 3);
+    u32_insert_space_at(&s, 3, 0);
+    u32_insert_space_at(&s, 1, 1);
+    u32_insert_space_at(&s, 10000, 2);
+
+    assert_int_equal(0, u32_strcmp(expected, s));
+
+    BFREE(s);
+    BFREE(expected);
+}
+
+
 /* vim: set cindent sw=4: */
\ No newline at end of file
diff --git a/utest/unicode_test.h b/utest/unicode_test.h
index 0ed1785..3e89522 100644
--- a/utest/unicode_test.h
+++ b/utest/unicode_test.h
@@ -28,6 +28,8 @@ void test_is_allowed_in_shape(void **state);
 void test_is_allowed_in_filename(void **state);
 void test_is_allowed_in_kv_string(void **state);
 void test_u32_strnrstr(void **state);
+void test_u32_insert_space_at(void **state);
+
 
 #endif