diff --git a/tests/test_keyhandlers.c b/tests/test_keyhandlers.c
index e01133e1..2e29ec6d 100644
--- a/tests/test_keyhandlers.c
+++ b/tests/test_keyhandlers.c
@@ -11,19 +11,36 @@
 
 static char line[INP_WIN_MAX];
 
+static int utf8_pos_to_col(char *str, int utf8_pos)
+{
+    int col = 0;
+
+    int i = 0;
+    for (i = 0; i<utf8_pos; i++) {
+        col++;
+        gchar *ch = g_utf8_offset_to_pointer(str, i);
+        gunichar uni = g_utf8_get_char(ch);
+        if (g_unichar_iswide(uni)) {
+            col++;
+        }
+    }
+
+    return col;
+}
+
 void append_non_wide_to_empty(void **state)
 {
     setlocale(LC_ALL, "");
     line[0] = '\0';
     int line_utf8_pos = 0;
-    int col = 0;
+    int col = utf8_pos_to_col(line, line_utf8_pos);
     int pad_start = 0;
 
     key_printable(line, &line_utf8_pos, &col, &pad_start, 'a', 80);
 
     assert_string_equal("a", line);
     assert_int_equal(line_utf8_pos, 1);
-    assert_int_equal(col, 1);
+    assert_int_equal(col, utf8_pos_to_col(line, line_utf8_pos));
     assert_int_equal(pad_start, 0);
 }
 
@@ -32,14 +49,14 @@ void append_wide_to_empty(void **state)
     setlocale(LC_ALL, "");
     line[0] = '\0';
     int line_utf8_pos = 0;
-    int col = 0;
+    int col = utf8_pos_to_col(line, line_utf8_pos);
     int pad_start = 0;
 
     key_printable(line, &line_utf8_pos, &col, &pad_start, 0x56DB, 80);
 
     assert_string_equal("四", line);
     assert_int_equal(line_utf8_pos, 1);
-    assert_int_equal(col, 2);
+    assert_int_equal(col, utf8_pos_to_col(line, line_utf8_pos));
     assert_int_equal(pad_start, 0);
 }
 
@@ -49,14 +66,14 @@ void append_non_wide_to_non_wide(void **state)
     strncpy(line, "a", 1);
     line[1] = '\0';
     int line_utf8_pos = 1;
-    int col = 1;
+    int col = utf8_pos_to_col(line, line_utf8_pos);
     int pad_start = 0;
 
     key_printable(line, &line_utf8_pos, &col, &pad_start, 'b', 80);
 
     assert_string_equal("ab", line);
     assert_int_equal(line_utf8_pos, 2);
-    assert_int_equal(col, 2);
+    assert_int_equal(col, utf8_pos_to_col(line, line_utf8_pos));
     assert_int_equal(pad_start, 0);
 }
 
@@ -66,14 +83,14 @@ void append_wide_to_non_wide(void **state)
     strncpy(line, "a", 1);
     line[1] = '\0';
     int line_utf8_pos = 1;
-    int col = 1;
+    int col = utf8_pos_to_col(line, line_utf8_pos);
     int pad_start = 0;
 
     key_printable(line, &line_utf8_pos, &col, &pad_start, 0x56DB, 80);
 
     assert_string_equal("a四", line);
     assert_int_equal(line_utf8_pos, 2);
-    assert_int_equal(col, 3);
+    assert_int_equal(col, utf8_pos_to_col(line, line_utf8_pos));
     assert_int_equal(pad_start, 0);
 }
 
@@ -83,14 +100,14 @@ void append_non_wide_to_wide(void **state)
     g_utf8_strncpy(line, "四", 1);
     line[strlen(line)] = '\0';
     int line_utf8_pos = 1;
-    int col = 2;
+    int col = utf8_pos_to_col(line, line_utf8_pos);
     int pad_start = 0;
 
     key_printable(line, &line_utf8_pos, &col, &pad_start, 'b', 80);
 
     assert_string_equal("四b", line);
     assert_int_equal(line_utf8_pos, 2);
-    assert_int_equal(col, 3);
+    assert_int_equal(col, utf8_pos_to_col(line, line_utf8_pos));
     assert_int_equal(pad_start, 0);
 }
 
@@ -100,14 +117,14 @@ void append_wide_to_wide(void **state)
     g_utf8_strncpy(line, "四", 1);
     line[strlen(line)] = '\0';
     int line_utf8_pos = 1;
-    int col = 2;
+    int col = utf8_pos_to_col(line, line_utf8_pos);
     int pad_start = 0;
 
     key_printable(line, &line_utf8_pos, &col, &pad_start, 0x4E09, 80);
 
     assert_string_equal("四三", line);
     assert_int_equal(line_utf8_pos, 2);
-    assert_int_equal(col, 4);
+    assert_int_equal(col, utf8_pos_to_col(line, line_utf8_pos));
     assert_int_equal(pad_start, 0);
 }
 
@@ -117,7 +134,7 @@ void append_no_wide_when_overrun(void **state)
     g_utf8_strncpy(line, "0123456789四1234567", 18);
     line[strlen(line)] = '\0';
     int line_utf8_pos = 18;
-    int col = 19;
+    int col = utf8_pos_to_col(line, line_utf8_pos);
     int pad_start = 0;
 
     key_printable(line, &line_utf8_pos, &col, &pad_start, 'z', 20);
@@ -126,7 +143,7 @@ void append_no_wide_when_overrun(void **state)
 
     assert_string_equal("0123456789四1234567zzz", line);
     assert_int_equal(line_utf8_pos, 21);
-    assert_int_equal(col, 22);
+    assert_int_equal(col, utf8_pos_to_col(line, line_utf8_pos));
     assert_int_equal(pad_start, 3);
 }
 
@@ -136,7 +153,7 @@ void append_wide_when_overrun(void **state)
     g_utf8_strncpy(line, "0123456789四1234567", 18);
     line[strlen(line)] = '\0';
     int line_utf8_pos = 18;
-    int col = 19;
+    int col = utf8_pos_to_col(line, line_utf8_pos);
     int pad_start = 0;
 
     key_printable(line, &line_utf8_pos, &col, &pad_start, 0x4E09, 20);
@@ -145,6 +162,74 @@ void append_wide_when_overrun(void **state)
 
     assert_string_equal("0123456789四1234567三三三", line);
     assert_int_equal(line_utf8_pos, 21);
-    assert_int_equal(col, 25);
+    assert_int_equal(col, utf8_pos_to_col(line, line_utf8_pos));
     assert_int_equal(pad_start, 6);
+}
+
+void insert_non_wide_to_non_wide(void **state)
+{
+    setlocale(LC_ALL, "");
+    g_utf8_strncpy(line, "abcd", 4);
+    line[strlen(line)] = '\0';
+    int line_utf8_pos = 2;
+    int col = utf8_pos_to_col(line, line_utf8_pos);
+    int pad_start = 0;
+
+    key_printable(line, &line_utf8_pos, &col, &pad_start, '0', 80);
+
+    assert_string_equal("ab0cd", line);
+    assert_int_equal(line_utf8_pos, 3);
+    assert_int_equal(col, utf8_pos_to_col(line, line_utf8_pos));
+    assert_int_equal(pad_start, 0);
+}
+
+void insert_wide_to_non_wide(void **state)
+{
+    setlocale(LC_ALL, "");
+    g_utf8_strncpy(line, "abcd", 26);
+    line[strlen(line)] = '\0';
+    int line_utf8_pos = 2;
+    int col = utf8_pos_to_col(line, line_utf8_pos);
+    int pad_start = 0;
+
+    key_printable(line, &line_utf8_pos, &col, &pad_start, 0x304C, 80);
+
+    assert_string_equal("abがcd", line);
+    assert_int_equal(line_utf8_pos, 3);
+    assert_int_equal(col, utf8_pos_to_col(line, line_utf8_pos));
+    assert_int_equal(pad_start, 0);
+}
+
+void insert_non_wide_to_wide(void **state)
+{
+    setlocale(LC_ALL, "");
+    g_utf8_strncpy(line, "ひらなひ", 4);
+    line[strlen(line)] = '\0';
+    int line_utf8_pos = 2;
+    int col = utf8_pos_to_col(line, line_utf8_pos);
+    int pad_start = 0;
+
+    key_printable(line, &line_utf8_pos, &col, &pad_start, '0', 80);
+
+    assert_string_equal("ひら0なひ", line);
+    assert_int_equal(line_utf8_pos, 3);
+    assert_int_equal(col, utf8_pos_to_col(line, line_utf8_pos));
+    assert_int_equal(pad_start, 0);
+}
+
+void insert_wide_to_wide(void **state)
+{
+    setlocale(LC_ALL, "");
+    g_utf8_strncpy(line, "ひらなひ", 4);
+    line[strlen(line)] = '\0';
+    int line_utf8_pos = 2;
+    int col = utf8_pos_to_col(line, line_utf8_pos);
+    int pad_start = 0;
+
+    key_printable(line, &line_utf8_pos, &col, &pad_start, 0x4E09, 80);
+
+    assert_string_equal("ひら三なひ", line);
+    assert_int_equal(line_utf8_pos, 3);
+    assert_int_equal(col, utf8_pos_to_col(line, line_utf8_pos));
+    assert_int_equal(pad_start, 0);
 }
\ No newline at end of file
diff --git a/tests/test_keyhandlers.h b/tests/test_keyhandlers.h
index 142a05ef..f70ee81e 100644
--- a/tests/test_keyhandlers.h
+++ b/tests/test_keyhandlers.h
@@ -8,4 +8,9 @@ void append_non_wide_to_wide(void **state);
 void append_wide_to_wide(void **state);
 
 void append_no_wide_when_overrun(void **state);
-void append_wide_when_overrun(void **state);
\ No newline at end of file
+void append_wide_when_overrun(void **state);
+
+void insert_non_wide_to_non_wide(void **state);
+void insert_wide_to_non_wide(void **state);
+void insert_non_wide_to_wide(void **state);
+void insert_wide_to_wide(void **state);
\ No newline at end of file
diff --git a/tests/testsuite.c b/tests/testsuite.c
index 4964d99d..3a60317e 100644
--- a/tests/testsuite.c
+++ b/tests/testsuite.c
@@ -632,6 +632,10 @@ int main(int argc, char* argv[]) {
         unit_test(append_wide_to_wide),
         unit_test(append_no_wide_when_overrun),
         unit_test(append_wide_when_overrun),
+        unit_test(insert_non_wide_to_non_wide),
+        unit_test(insert_wide_to_non_wide),
+        unit_test(insert_non_wide_to_wide),
+        unit_test(insert_wide_to_wide),
     };
 
     return run_tests(all_tests);