diff --git a/src/prompt_toolkit/formatted_text/ansi.py b/src/prompt_toolkit/formatted_text/ansi.py
index 2f355c2b7..ad992abb6 100644
--- a/src/prompt_toolkit/formatted_text/ansi.py
+++ b/src/prompt_toolkit/formatted_text/ansi.py
@@ -119,7 +119,8 @@ def _parse_corot(self) -> Generator[None, str, None]:
 
                         # Check and evaluate cursor forward
                         elif char == "C":
-                            for i in range(params[0]):
+                            # A missing or zero count defaults to one column.
+                            for i in range(params[0] or 1):
                                 # add <SPACE> using current style
                                 formatted_text.append((style, " "))
                             break
diff --git a/tests/test_formatted_text.py b/tests/test_formatted_text.py
index a111a7f20..9fe9ef24a 100644
--- a/tests/test_formatted_text.py
+++ b/tests/test_formatted_text.py
@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+import pytest
+
 from prompt_toolkit.formatted_text import (
     ANSI,
     HTML,
@@ -145,6 +147,19 @@ def test_ansi_true_color():
     ]
 
 
+@pytest.mark.parametrize("csi", ["\x1b[", "\x9b"])
+@pytest.mark.parametrize(
+    "parameter, count", [("", 1), ("0", 1), ("00", 1), ("1", 1), ("3", 3)]
+)
+@pytest.mark.parametrize("color, style", [("", ""), ("31", "ansired")])
+def test_ansi_cursor_forward_defaults(csi, parameter, count, color, style):
+    value = ANSI(f"{csi}{color}ma{csi}{parameter}Cb{csi}0mc")
+
+    assert to_formatted_text(value) == (
+        [(style, "a")] + [(style, " ")] * count + [(style, "b"), ("", "c")]
+    )
+
+
 def test_ansi_interpolation():
     # %-style interpolation.
     value = ANSI("\x1b[1m%s\x1b[0m") % "hello\x1b"