diff --git a/fontbox/src/main/java/org/apache/fontbox/ttf/gsub/GlyphSubstitutionDataExtractor.java b/fontbox/src/main/java/org/apache/fontbox/ttf/gsub/GlyphSubstitutionDataExtractor.java
index b4a15dda796..c6da65ac09e 100644
--- a/fontbox/src/main/java/org/apache/fontbox/ttf/gsub/GlyphSubstitutionDataExtractor.java
+++ b/fontbox/src/main/java/org/apache/fontbox/ttf/gsub/GlyphSubstitutionDataExtractor.java
@@ -220,8 +220,8 @@ private void extractDataFromSingleSubstTableFormat2Table(
 
         if (coverageTable.getSize() != singleSubstTableFormat2.getSubstituteGlyphIDs().length)
         {
-            throw new IllegalArgumentException(
-                    "The no. coverage table entries should be the same as the size of the substituteGlyphIDs");
+            LOG.warn("The no. coverage table entries should be the same as the size of the substituteGlyphIDs");
+            return;
         }
 
         for (int i = 0; i < coverageTable.getSize(); i++)
@@ -242,8 +242,8 @@ private void extractDataFromMultipleSubstitutionFormat1Table(
 
         if (coverageTable.getSize() != multipleSubstFormat1Subtable.getSequenceTables().length)
         {
-            throw new IllegalArgumentException(
-                    "The no. coverage table entries should be the same as the size of the sequencce tables");
+            LOG.warn("The no. coverage table entries should be the same as the size of the sequencce tables");
+            return;
         }
 
         for (int i = 0; i < coverageTable.getSize(); i++)