diff --git a/core/queryparser/sparql/src/main/java/org/eclipse/rdf4j/query/parser/sparql/ast/ASTServiceGraphPattern.java b/core/queryparser/sparql/src/main/java/org/eclipse/rdf4j/query/parser/sparql/ast/ASTServiceGraphPattern.java
index b30eda87f36..1f7e38567dd 100644
--- a/core/queryparser/sparql/src/main/java/org/eclipse/rdf4j/query/parser/sparql/ast/ASTServiceGraphPattern.java
+++ b/core/queryparser/sparql/src/main/java/org/eclipse/rdf4j/query/parser/sparql/ast/ASTServiceGraphPattern.java
@@ -57,11 +57,8 @@ public boolean isSilent() {
 	public String getPatternString() {
 
 		if (patternString == null) {
-			ASTOperationContainer parentContainer = (ASTOperationContainer) getParentContainer(this);
-
-			String sourceString = parentContainer.getSourceString();
-
 			// snip away line until begin token line position
+			String sourceString = getSourceString();
 			String substring = sourceString;
 			for (int i = 1; i < getBeginTokenLinePos(); i++) {
 				substring = substring.substring(substring.indexOf('\n') + 1);
@@ -84,6 +81,27 @@ public String getPatternString() {
 		return patternString;
 	}
 
+	private String getSourceString() {
+		Node theParent = getParentContainer(this);
+		String sourceString = null;
+		if (theParent instanceof ASTOperationContainer) {
+			sourceString = ((ASTOperationContainer) theParent).getSourceString();
+		} else if (theParent instanceof ASTUpdateSequence) {
+			sourceString = ((ASTUpdateSequence) theParent).getSourceString();
+		}
+
+		while (sourceString == null && theParent != null) {
+			theParent = theParent.jjtGetParent();
+			if (theParent == null) {
+				break;
+			}
+			if (theParent instanceof ASTUpdateSequence) {
+				sourceString = ((ASTUpdateSequence) theParent).getSourceString();
+			}
+		}
+		return sourceString;
+	}
+
 	private Node getParentContainer(Node node) {
 		if (node instanceof ASTOperationContainer || node == null) {
 			return node;
diff --git a/core/queryparser/sparql/src/test/java/org/eclipse/rdf4j/query/parser/sparql/TestServiceUpdateExprBuilder.java b/core/queryparser/sparql/src/test/java/org/eclipse/rdf4j/query/parser/sparql/TestServiceUpdateExprBuilder.java
new file mode 100644
index 00000000000..b6b55594855
--- /dev/null
+++ b/core/queryparser/sparql/src/test/java/org/eclipse/rdf4j/query/parser/sparql/TestServiceUpdateExprBuilder.java
@@ -0,0 +1,37 @@
+/*******************************************************************************
+ * Copyright (c) 2020 Eclipse RDF4J contributors.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Distribution License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *******************************************************************************/
+package org.eclipse.rdf4j.query.parser.sparql;
+
+import org.eclipse.rdf4j.query.algebra.Service;
+import org.eclipse.rdf4j.query.parser.ParsedUpdate;
+import org.junit.Test;
+
+public class TestServiceUpdateExprBuilder {
+
+	/**
+	 * The test reproduces a {@link NullPointerException} that is thrown when parsing an update with several update
+	 * expressions and one of these contain {@link Service} operator The NPE is thrown because the sourceString is set
+	 * to the outermost operation container
+	 */
+	@Test
+	public void testServiceWithMultipleUpdateExpr() {
+		SPARQLParser parser = new SPARQLParser();
+		String updateStr = "PREFIX family: <http://examples.ontotext.com/family#>\n" +
+				"DROP ALL ;\n" +
+				"INSERT {\n" +
+				"    family:Alice family:knows family:Bob .\n" +
+				"}\n" +
+				"WHERE {\n" +
+				"    SERVICE <repository:1> {\n" +
+				"        family:Alice family:knows family:Bob .\n" +
+				"    }\n" +
+				"}";
+		// should not throw NPE, but prior to 3.1.3 it does
+		parser.parseUpdate(updateStr, null);
+	}
+}