diff --git a/wcag-validation/src/main/java/org/verapdf/gf/model/factory/chunks/ChunkParser.java b/wcag-validation/src/main/java/org/verapdf/gf/model/factory/chunks/ChunkParser.java
index e1d81f75b..c577739a3 100644
--- a/wcag-validation/src/main/java/org/verapdf/gf/model/factory/chunks/ChunkParser.java
+++ b/wcag-validation/src/main/java/org/verapdf/gf/model/factory/chunks/ChunkParser.java
@@ -37,6 +37,7 @@
 import org.verapdf.pd.colors.PDDeviceRGB;
 import org.verapdf.pd.font.PDCIDFont;
 import org.verapdf.pd.font.PDFontDescriptor;
+import org.verapdf.pd.font.type3.PDType3Font;
 import org.verapdf.pd.images.PDXForm;
 import org.verapdf.pd.images.PDXObject;
 import org.verapdf.pd.optionalcontent.PDOCMDDictionary;
@@ -886,6 +887,19 @@ private void parseString(boolean isVertical, COSString string, TextPieces textPi
 						LOGGER.log(Level.WARNING, "The glyph can not be mapped to Unicode");
 					}
 				}
+                if (font instanceof PDType3Font) {
+                    Double glyphAscent = ((PDType3Font) font).getAscentFromProgram(code);
+                    if (glyphAscent != null && (textPieces.getAscent() == null ||
+                            glyphAscent > textPieces.getAscent())) {
+                        textPieces.setAscent(glyphAscent);
+                    }
+                    Double glyphDescent = ((PDType3Font) font).getDescentFromProgram(code);
+                    if (glyphDescent != null && (textPieces.getDescent() == null ||
+                            glyphDescent < textPieces.getDescent())) {
+                        textPieces.setDescent(glyphDescent);
+                    }
+                }
+
 				textPieces.add(new TextPieces.TextPiece(value, current, current + width));
 				textPieces.shiftCurrent(shift);
 			}
@@ -934,7 +948,7 @@ private TextChunk createTextChunk(List<COSBase> arguments, String operatorType,
 			PDFontDescriptor descriptor = font.getFontDescriptor();
 			String fontNameWithoutSubset = font.getNameWithoutSubset();
 			TextChunk textChunk = new TextChunk(
-				TextChunksHelper.calculateTextBoundingBox(isVertical, textRenderingMatrixBefore, textRenderingMatrixAfter, font, pageNumber),
+				TextChunksHelper.calculateTextBoundingBox(isVertical, textRenderingMatrixBefore, textRenderingMatrixAfter, font, pageNumber, textPieces),
 				textPieces.getValue(), fontNameWithoutSubset, TextChunksHelper.calculateTextSize(textRenderingMatrixAfter),
 				TextChunksHelper.calculateFontWeight(graphicsState.getTextState().getRenderingMode(), font), 
 					descriptor.getItalicAngle(), TextChunksHelper.calculateTextBaseLine(textRenderingMatrixAfter),
diff --git a/wcag-validation/src/main/java/org/verapdf/gf/model/factory/chunks/TextChunksHelper.java b/wcag-validation/src/main/java/org/verapdf/gf/model/factory/chunks/TextChunksHelper.java
index 1892a6094..22fc489fc 100644
--- a/wcag-validation/src/main/java/org/verapdf/gf/model/factory/chunks/TextChunksHelper.java
+++ b/wcag-validation/src/main/java/org/verapdf/gf/model/factory/chunks/TextChunksHelper.java
@@ -46,21 +46,21 @@ protected static COSBase getArgument(List<COSBase> arguments, String operatorTyp
 	}
 
 	protected static BoundingBox calculateTextBoundingBox(boolean isVertical, Matrix textRenderingMatrixBefore, 
-														  Matrix textRenderingMatrixAfter, PDFont font, Integer pageNumber) {
+														  Matrix textRenderingMatrixAfter, PDFont font, Integer pageNumber, TextPieces textPieces) {
 		return isVertical ? TextChunksHelper.calculateTextBoundingBoxV(textRenderingMatrixBefore, textRenderingMatrixAfter, pageNumber)
-				: TextChunksHelper.calculateTextBoundingBoxH(textRenderingMatrixBefore, textRenderingMatrixAfter, font, pageNumber);
+				: TextChunksHelper.calculateTextBoundingBoxH(textRenderingMatrixBefore, textRenderingMatrixAfter, font, pageNumber, textPieces);
 	}
 
 	private static BoundingBox calculateTextBoundingBoxH(Matrix textRenderingMatrixBefore, Matrix textRenderingMatrixAfter, 
-														   PDFont font, Integer pageNumber) {
+														   PDFont font, Integer pageNumber, TextPieces textPieces) {
 		double[] fontBoundingBox = font.getBoundingBox();
 		Double descent = font.getDescent();
 		if (descent == null) {
-			descent = fontBoundingBox[1];
+            descent = textPieces.getDescent() != null ? textPieces.getDescent() : fontBoundingBox[1];
 		}
 		Double ascent = font.getAscent();
 		if (ascent == null) {
-			ascent = fontBoundingBox[3];
+			ascent = textPieces.getAscent() != null ? textPieces.getAscent() : fontBoundingBox[3];
 		}
 		double x1;
 		double x2;
diff --git a/wcag-validation/src/main/java/org/verapdf/gf/model/factory/chunks/TextPieces.java b/wcag-validation/src/main/java/org/verapdf/gf/model/factory/chunks/TextPieces.java
index 75019bdc1..300d94c1e 100644
--- a/wcag-validation/src/main/java/org/verapdf/gf/model/factory/chunks/TextPieces.java
+++ b/wcag-validation/src/main/java/org/verapdf/gf/model/factory/chunks/TextPieces.java
@@ -33,6 +33,8 @@ public class TextPieces {
 	public final boolean isVertical;
 	private int currentIndex;
 	private double current;
+    private Double ascent;
+    private Double descent;
 
 	TextPieces(boolean isVertical) {
 		this.isVertical = isVertical;
@@ -132,7 +134,23 @@ public List<StreamInfo> getStreamInfos(int operatorIndex, String xObjectName) {
 			}
 		}
 		return streamInfos;
-	} 
+	}
+
+    public Double getAscent() {
+        return ascent;
+    }
+
+    public void setAscent(double ascent) {
+        this.ascent = ascent;
+    }
+
+    public Double getDescent() {
+        return descent;
+    }
+
+    public void setDescent(double descent) {
+        this.descent = descent;
+    }
 
 	public static class TextPiece {
 		private final String value;