diff --git a/org.eclipse.lemminx/src/main/java/org/eclipse/lemminx/extensions/xsi/participants/XSIFormatterParticipant.java b/org.eclipse.lemminx/src/main/java/org/eclipse/lemminx/extensions/xsi/participants/XSIFormatterParticipant.java
index 53cc93df0..b9e27e4b7 100644
--- a/org.eclipse.lemminx/src/main/java/org/eclipse/lemminx/extensions/xsi/participants/XSIFormatterParticipant.java
+++ b/org.eclipse.lemminx/src/main/java/org/eclipse/lemminx/extensions/xsi/participants/XSIFormatterParticipant.java
@@ -216,20 +216,22 @@ public boolean formatAttributeValue(DOMAttr attr, XMLFormatterDocument formatter
 					indentSpaceOffset = (attrValueStart + 1) - attr.getNodeAttrName().getStart()
 							+ (parentConstraints.getIndentLevel() + 1) * tabSize;
 				}
+				int attrValuelength = attrValueStart - indentSpaceOffset + attr.getValue().length();
 				// Insert newline and indent where required based on setting
 				if (locationNum % lineFeed == 0) {
 					formatterDocument.replaceLeftSpacesWithIndentationWithOffsetSpaces(indentSpaceOffset,
 							attrValueStart, attrValueStart + i + 1, true, edits);
+					availableLineWidth = formatterDocument.getMaxLineWidth() - attrValuelength;
 				} else {
 					formatterDocument.replaceLeftSpacesWithOneSpace(indentSpaceOffset, attrValueStart + i + 1, edits);
+					availableLineWidth = availableLineWidth - attrValuelength;
 				}
 				locationNum++;
 			}
 		}
 		if (formatterDocument.isMaxLineWidthSupported() && attr.getValue() != null) {
 			parentConstraints
-					.setAvailableLineWidth(formatterDocument.getMaxLineWidth() - (attrValueStart - indentSpaceOffset)
-							- attr.getValue().length());
+					.setAvailableLineWidth(availableLineWidth);
 		}
 		return true;
 	}
diff --git a/org.eclipse.lemminx/src/test/java/org/eclipse/lemminx/services/format/settings/XMLFormatterMaxLineWithTest.java b/org.eclipse.lemminx/src/test/java/org/eclipse/lemminx/services/format/settings/XMLFormatterMaxLineWithTest.java
index 8cc2ac040..b638424a1 100644
--- a/org.eclipse.lemminx/src/test/java/org/eclipse/lemminx/services/format/settings/XMLFormatterMaxLineWithTest.java
+++ b/org.eclipse.lemminx/src/test/java/org/eclipse/lemminx/services/format/settings/XMLFormatterMaxLineWithTest.java
@@ -605,9 +605,39 @@ public void commentFormattingLineBreakingEarlyAtMaxLineWidth() throws BadLocatio
 				"-->\r\n" + //
 				"</foo>";
 		assertFormat(content, expected, settings, //
-				te(4, 95, 4,96, "\r\n"));
+				te(4, 95, 4, 96, "\r\n"));
 		assertFormat(expected, expected, settings);
+	}
 
+	// https://github.com/eclipse/lemminx/issues/1439
+	@Test
+	public void firstLineNoBreakAtMaxLineWidth() throws BadLocationException {
+		SharedSettings settings = new SharedSettings();
+		settings.getFormattingSettings().setMaxLineWidth(160);
+		String content = "<project xmlns=\"http://maven.apache.org/POM/4.0.0\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xsi:schemaLocation=\"http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd\"></project>";
+		String expected = "<project xmlns=\"http://maven.apache.org/POM/4.0.0\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\""
+				+ System.lineSeparator() + //
+				"  xsi:schemaLocation=\"http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd\"></project>";
+		assertFormat(content, expected, settings, //
+				te(0, 104, 0, 105, System.lineSeparator() + "  "));
+		assertFormat(expected, expected, settings);
+	}
+
+	// https://github.com/eclipse/lemminx/issues/1439
+	@Test
+	public void firstLineNoBreakAtMaxLineWidthDefaultWidth() throws BadLocationException {
+		SharedSettings settings = new SharedSettings();
+		settings.getFormattingSettings().setMaxLineWidth(100); // default max line width
+		String content = "<project xmlns=\"http://maven.apache.org/POM/4.0.0\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xsi:schemaLocation=\"http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd\"></project>";
+		String expected = "<project xmlns=\"http://maven.apache.org/POM/4.0.0\""
+				+ System.lineSeparator() + //
+				"  xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\""
+				+ System.lineSeparator() + //
+				"  xsi:schemaLocation=\"http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd\"></project>";
+		assertFormat(content, expected, settings, //
+				te(0, 50, 0, 51, System.lineSeparator() + "  "), //
+				te(0, 104, 0, 105, System.lineSeparator() + "  "));
+		assertFormat(expected, expected, settings);
 	}
 
 	private static void assertFormat(String unformatted, String expected, SharedSettings sharedSettings,
@@ -615,4 +645,4 @@ private static void assertFormat(String unformatted, String expected, SharedSett
 			throws BadLocationException {
 		XMLAssert.assertFormat(null, unformatted, expected, sharedSettings, "test.xml", Boolean.FALSE, expectedEdits);
 	}
-}
+}
\ No newline at end of file