diff --git a/extensions/wikidata/src/org/openrefine/wikidata/qa/scrutinizers/FormatScrutinizer.java b/extensions/wikidata/src/org/openrefine/wikidata/qa/scrutinizers/FormatScrutinizer.java
index 2151687fc..bacdcc936 100644
--- a/extensions/wikidata/src/org/openrefine/wikidata/qa/scrutinizers/FormatScrutinizer.java
+++ b/extensions/wikidata/src/org/openrefine/wikidata/qa/scrutinizers/FormatScrutinizer.java
@@ -24,6 +24,8 @@
 package org.openrefine.wikidata.qa.scrutinizers;
 
 import org.openrefine.wikidata.qa.QAWarning;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.wikidata.wdtk.datamodel.interfaces.EntityIdValue;
 import org.wikidata.wdtk.datamodel.interfaces.PropertyIdValue;
 import org.wikidata.wdtk.datamodel.interfaces.Snak;
@@ -38,6 +40,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.regex.Pattern;
+import java.util.regex.PatternSyntaxException;
 
 /**
  * A scrutinizer that detects incorrect formats in text values (mostly
@@ -48,6 +51,8 @@ import java.util.regex.Pattern;
  */
 public class FormatScrutinizer extends SnakScrutinizer {
 
+    private static final Logger logger = LoggerFactory.getLogger(FormatScrutinizer.class);
+
     public static final String type = "add-statements-with-invalid-format";
     public String formatConstraintQid;
     public String formatRegexPid;
@@ -97,9 +102,14 @@ public class FormatScrutinizer extends SnakScrutinizer {
                 String regex = constraint.regularExpressionFormat;
                 Pattern pattern = null;
                 if (regex != null) {
-                    pattern = Pattern.compile(regex);
+                    try {
+                        pattern = Pattern.compile(regex);
+                        patterns.add(pattern);
+                    } catch(PatternSyntaxException e) {
+                        logger.info(String.format("Ignoring invalid format constraint for property %s. Regex %s is invalid: %s",
+                                pid.getId(), regex, e.getMessage()));
+                    }
                 }
-                patterns.add(pattern);
             }
             _patterns.put(pid, patterns);
             return patterns;
diff --git a/extensions/wikidata/tests/src/org/openrefine/wikidata/qa/scrutinizers/FormatScrutinizerTest.java b/extensions/wikidata/tests/src/org/openrefine/wikidata/qa/scrutinizers/FormatScrutinizerTest.java
index c13247fba..f13885f7e 100644
--- a/extensions/wikidata/tests/src/org/openrefine/wikidata/qa/scrutinizers/FormatScrutinizerTest.java
+++ b/extensions/wikidata/tests/src/org/openrefine/wikidata/qa/scrutinizers/FormatScrutinizerTest.java
@@ -54,6 +54,7 @@ public class FormatScrutinizerTest extends ScrutinizerTest {
     public static Value noMatchValue = Datamodel.makeStringValue("image");
     public static Value incompleteMatchValue = Datamodel.makeStringValue(".jpg");
     public static String regularExpression = "(?i).+\\.(jpg|jpeg|jpe|png|svg|tif|tiff|gif|xcf|pdf|djvu|webp)";
+    public static String invalidRegularExpression = "(?[A-Za-z]+)";
 
     public static ItemIdValue entityIdValue = Datamodel.makeWikidataItemIdValue(FORMAT_CONSTRAINT_QID);
     public static PropertyIdValue regularExpressionParameter = Datamodel.makeWikidataPropertyIdValue(FORMAT_REGEX_PID);
@@ -72,11 +73,7 @@ public class FormatScrutinizerTest extends ScrutinizerTest {
         Statement statement = new StatementImpl("P18", value, idA);
         ItemUpdate updateA = new ItemUpdateBuilder(idA).addStatement(statement).build();
 
-        Snak qualifierSnak = Datamodel.makeValueSnak(regularExpressionParameter, regularExpressionFormat);
-        List<Snak> qualifierSnakList = Collections.singletonList(qualifierSnak);
-        SnakGroup qualifierSnakGroup = Datamodel.makeSnakGroup(qualifierSnakList);
-        List<SnakGroup> constraintQualifiers = Collections.singletonList(qualifierSnakGroup);
-        List<Statement> constraintDefinitions = constraintParameterStatementList(entityIdValue, constraintQualifiers);
+        List<Statement> constraintDefinitions = generateFormatConstraint(regularExpression);
 
         ConstraintFetcher fetcher = mock(ConstraintFetcher.class);
         when(fetcher.getConstraintsByType(propertyIdValue, FORMAT_CONSTRAINT_QID)).thenReturn(constraintDefinitions);
@@ -92,11 +89,7 @@ public class FormatScrutinizerTest extends ScrutinizerTest {
         Statement statement = new StatementImpl("P18", value, idA);
         ItemUpdate updateA = new ItemUpdateBuilder(idA).addStatement(statement).build();
 
-        Snak qualifierSnak = Datamodel.makeValueSnak(regularExpressionParameter, regularExpressionFormat);
-        List<Snak> qualifierSnakList = Collections.singletonList(qualifierSnak);
-        SnakGroup qualifierSnakGroup = Datamodel.makeSnakGroup(qualifierSnakList);
-        List<SnakGroup> constraintQualifiers = Collections.singletonList(qualifierSnakGroup);
-        List<Statement> constraintDefinitions = constraintParameterStatementList(entityIdValue, constraintQualifiers);
+        List<Statement> constraintDefinitions = generateFormatConstraint(regularExpression);
 
         ConstraintFetcher fetcher = mock(ConstraintFetcher.class);
         when(fetcher.getConstraintsByType(propertyIdValue, FORMAT_CONSTRAINT_QID)).thenReturn(constraintDefinitions);
@@ -112,11 +105,7 @@ public class FormatScrutinizerTest extends ScrutinizerTest {
         Statement statement = new StatementImpl("P18", value, idA);
         ItemUpdate updateA = new ItemUpdateBuilder(idA).addStatement(statement).build();
 
-        Snak qualifierSnak = Datamodel.makeValueSnak(regularExpressionParameter, regularExpressionFormat);
-        List<Snak> qualifierSnakList = Collections.singletonList(qualifierSnak);
-        SnakGroup qualifierSnakGroup = Datamodel.makeSnakGroup(qualifierSnakList);
-        List<SnakGroup> constraintQualifiers = Collections.singletonList(qualifierSnakGroup);
-        List<Statement> constraintDefinitions = constraintParameterStatementList(entityIdValue, constraintQualifiers);
+        List<Statement> constraintDefinitions = generateFormatConstraint(regularExpression);
 
         ConstraintFetcher fetcher = mock(ConstraintFetcher.class);
         when(fetcher.getConstraintsByType(propertyIdValue, FORMAT_CONSTRAINT_QID)).thenReturn(constraintDefinitions);
@@ -124,5 +113,29 @@ public class FormatScrutinizerTest extends ScrutinizerTest {
         scrutinize(updateA);
         assertWarningsRaised(FormatScrutinizer.type);
     }
+    
+    @Test
+    public void testInvalidRegex() {
+        ItemIdValue idA = TestingData.existingId;
+        ValueSnak value = Datamodel.makeValueSnak(propertyIdValue, incompleteMatchValue);
+        Statement statement = new StatementImpl("P18", value, idA);
+        ItemUpdate updateA = new ItemUpdateBuilder(idA).addStatement(statement).build();
+        
+        List<Statement> constraintDefinitions = generateFormatConstraint(invalidRegularExpression);
+
+        ConstraintFetcher fetcher = mock(ConstraintFetcher.class);
+        when(fetcher.getConstraintsByType(propertyIdValue, FORMAT_CONSTRAINT_QID)).thenReturn(constraintDefinitions);
+        setFetcher(fetcher);
+        scrutinize(updateA);
+        assertNoWarningRaised();
+    }
+    
+    protected List<Statement> generateFormatConstraint(String regex) {
+        Snak qualifierSnak = Datamodel.makeValueSnak(regularExpressionParameter, Datamodel.makeStringValue(regex));
+        List<Snak> qualifierSnakList = Collections.singletonList(qualifierSnak);
+        SnakGroup qualifierSnakGroup = Datamodel.makeSnakGroup(qualifierSnakList);
+        List<SnakGroup> constraintQualifiers = Collections.singletonList(qualifierSnakGroup);
+        return constraintParameterStatementList(entityIdValue, constraintQualifiers);
+    }
 
 }