diff --git a/novelwriter/core/docbuild.py b/novelwriter/core/docbuild.py
index 1556c5a5..cc9d1e50 100644
--- a/novelwriter/core/docbuild.py
+++ b/novelwriter/core/docbuild.py
@@ -140,6 +140,9 @@ class NWBuildDocument:
 
     def iterBuildDocument(self, path: Path, bFormat: nwBuildFmt) -> Iterable[tuple[int, bool]]:
         """Wrapper for builders based on format."""
+        self._error = None
+        self._cache = None
+
         if bFormat in (nwBuildFmt.J_HTML, nwBuildFmt.J_NWD):
             # Ensure that JSON output has the correct extension
             path = path.with_suffix(".json")
diff --git a/tests/test_core/test_core_docbuild.py b/tests/test_core/test_core_docbuild.py
index 23feea8b..147e6870 100644
--- a/tests/test_core/test_core_docbuild.py
+++ b/tests/test_core/test_core_docbuild.py
@@ -34,6 +34,7 @@ from novelwriter.enum import nwBuildFmt
 from novelwriter.formats.tohtml import ToHtml
 from novelwriter.formats.tomarkdown import ToMarkdown
 from novelwriter.formats.toodt import ToOdt
+from novelwriter.formats.toqdoc import ToQTextDocument
 from novelwriter.formats.toraw import ToRaw
 
 from tests.mocked import causeException, causeOSError
@@ -588,3 +589,17 @@ def testCoreDocBuild_IterBuild(mockGUI, fncPath: Path, mockRnd):
     assert "meta" in data
     assert "text" in data
     docFile.unlink()
+
+    # PDF Format
+    docFile = fncPath / "Minimal.pdf"
+    assert list(docBuild.iterBuildDocument(docFile, nwBuildFmt.PDF)) == [
+        (0, True), (1, True), (2, False), (3, True), (4, True),
+        (5, True), (6, True), (7, True), (8, True), (9, False),
+    ]
+    assert isinstance(docBuild.lastBuild, ToQTextDocument)
+    assert docFile.is_file()
+    docFile.unlink()
+
+    # Invalid Format
+    assert list(docBuild.iterBuildDocument(docFile, None)) == []  # type: ignore
+    assert docBuild.lastBuild is None