diff --git a/src/main/java/com/xmlcalabash/extensions/fileutils/Info.java b/src/main/java/com/xmlcalabash/extensions/fileutils/Info.java
index a77eadd0..de3b6624 100644
--- a/src/main/java/com/xmlcalabash/extensions/fileutils/Info.java
+++ b/src/main/java/com/xmlcalabash/extensions/fileutils/Info.java
@@ -14,6 +14,7 @@
 import com.xmlcalabash.util.MessageFormatter;
 import com.xmlcalabash.util.TreeWriter;
 import com.xmlcalabash.util.S9apiUtils;
+import com.xmlcalabash.util.URIUtils;
 import net.sf.saxon.s9api.QName;
 import net.sf.saxon.s9api.SaxonApiException;
 import net.sf.saxon.s9api.XdmNode;
@@ -97,7 +98,7 @@ public void run() throws SaxonApiException {
         tree.startDocument(step.getNode().getBaseURI());
 
         if ("file".equals(uri.getScheme())) {
-            File file = new File(uri.getPath());
+            File file = URIUtils.toFile(uri);
 
             if (!file.exists()) {
                 if (failOnError) {
diff --git a/src/main/java/com/xmlcalabash/extensions/fileutils/Tempfile.java b/src/main/java/com/xmlcalabash/extensions/fileutils/Tempfile.java
index 36bb0713..a30932c2 100644
--- a/src/main/java/com/xmlcalabash/extensions/fileutils/Tempfile.java
+++ b/src/main/java/com/xmlcalabash/extensions/fileutils/Tempfile.java
@@ -9,6 +9,7 @@
 import com.xmlcalabash.runtime.XAtomicStep;
 import com.xmlcalabash.model.RuntimeValue;
 import com.xmlcalabash.util.TreeWriter;
+import com.xmlcalabash.util.URIUtils;
 import net.sf.saxon.s9api.QName;
 import net.sf.saxon.s9api.SaxonApiException;
 
@@ -79,7 +80,7 @@ public void run() throws SaxonApiException {
         if (!"file".equals(uri.getScheme())) {
             throw new XProcException(step.getNode(), "Only file: scheme URIs are supported by the tempfile step.");
         } else {
-            file = new File(uri.getPath());
+            file = URIUtils.toFile(uri);
         }
 
         if (!file.isDirectory()) {
diff --git a/src/main/java/com/xmlcalabash/io/FileDataStore.java b/src/main/java/com/xmlcalabash/io/FileDataStore.java
index 05d367c1..a44de29d 100644
--- a/src/main/java/com/xmlcalabash/io/FileDataStore.java
+++ b/src/main/java/com/xmlcalabash/io/FileDataStore.java
@@ -21,6 +21,7 @@
 package com.xmlcalabash.io;
 
 import com.xmlcalabash.core.XProcException;
+import com.xmlcalabash.util.URIUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -67,7 +68,7 @@ public URI writeEntry(String href, String base, String media,
 		URI baseURI = URI.create(base);
 		URI uri = baseURI.resolve(href);
 		if ("file".equalsIgnoreCase(uri.getScheme())) {
-			File file = new File(uri);
+			File file = URIUtils.toFile(uri);
 			String suffix = getFileSuffixFromType(media);
 			if (file.isDirectory() || uri.getPath().endsWith("/")) {
 				if (!file.isDirectory() && !file.mkdirs()) {
@@ -114,7 +115,7 @@ public void readEntry(String href, String base, String accept,
 		URI baseURI = URI.create(base);
 		URI uri = baseURI.resolve(href);
 		if ("file".equalsIgnoreCase(uri.getScheme())) {
-			File file = new File(uri);
+			File file = URIUtils.toFile(uri);
 			String type = getContentTypeFromName(file.getName());
             if (overrideContentType != null) {
                 type = overrideContentType;
@@ -136,7 +137,7 @@ public void infoEntry(String href, String base, String accept,
 		URI baseURI = URI.create(base);
 		URI uri = baseURI.resolve(href);
 		if ("file".equalsIgnoreCase(uri.getScheme())) {
-			File file = new File(uri);
+			File file = URIUtils.toFile(uri);
 			String type;
 			if (file.isFile()) {
 				type = getContentTypeFromName(file.getName());
@@ -157,7 +158,7 @@ public void listEachEntry(String href, String base, String accept,
 		URI baseURI = URI.create(base);
 		URI uri = baseURI.resolve(href);
 		if ("file".equalsIgnoreCase(uri.getScheme())) {
-			File file = new File(uri);
+			File file = URIUtils.toFile(uri);
 
             if (!file.canRead()) {
                 throw XProcException.stepError(12);
@@ -186,7 +187,7 @@ public URI createList(String href, String base)
 		URI baseURI = URI.create(base);
 		URI uri = baseURI.resolve(href);
 		if ("file".equalsIgnoreCase(uri.getScheme())) {
-			File file = new File(uri);
+			File file = URIUtils.toFile(uri);
 			if (file.isDirectory()) {
 				return file.toURI();
 			} else if (file.exists()) {
@@ -209,7 +210,7 @@ public void deleteEntry(String href, String base)
 		URI baseURI = URI.create(base);
 		URI uri = baseURI.resolve(href);
 		if ("file".equalsIgnoreCase(uri.getScheme())) {
-			File file = new File(uri);
+			File file = URIUtils.toFile(uri);
 			if (!file.exists()) {
 				throw new FileNotFoundException(file.toURI().toASCIIString());
 			} else if (!file.delete()) {
diff --git a/src/main/java/com/xmlcalabash/util/URIUtils.java b/src/main/java/com/xmlcalabash/util/URIUtils.java
index e5221a2c..a25da728 100644
--- a/src/main/java/com/xmlcalabash/util/URIUtils.java
+++ b/src/main/java/com/xmlcalabash/util/URIUtils.java
@@ -100,4 +100,16 @@ public static URI makeAbsolute(String localFn) {
         URI cwd = cwdAsURI();
         return cwd.resolve(encode(localFn));
     }
+
+    public static File toFile(URI uri) {
+        if (!"file".equalsIgnoreCase(uri.getScheme())) {
+            throw new IllegalStateException("Expecting a file URI: " + uri.toASCIIString());
+        }
+
+        if (uri.getAuthority() != null && uri.getAuthority().length() > 0) {
+            return new File("//"+uri.getAuthority()+uri.getPath());
+        } else {
+            return new File(uri.getPath());
+        }
+    }
 }