diff --git a/README.md b/README.md
index 2e545c44..42fd812b 100644
--- a/README.md
+++ b/README.md
@@ -4,7 +4,7 @@ An implementation of the [JSON-LD 1.1](https://www.w3.org/TR/json-ld/) (JSON-bas
 
 The goals of Titanium are:
 - conformance to the specification
-- secure, stable, fast, A+ code
+- secure, stable, fast, A+ code (1700 tests)
 - minimal external dependencies
   - only `jakarta.json-api` is required
 - simple to use
diff --git a/src/main/java/com/apicatalog/jsonld/uri/UriResolver.java b/src/main/java/com/apicatalog/jsonld/uri/UriResolver.java
index f6c91392..e60b771c 100644
--- a/src/main/java/com/apicatalog/jsonld/uri/UriResolver.java
+++ b/src/main/java/com/apicatalog/jsonld/uri/UriResolver.java
@@ -149,7 +149,7 @@ private static final String[] resolveAsComponents(final URI base, final URI rela
                 } else {
                     target[2] = basePath;
 
-                    if (UriUtils.isDefined(relative.getQuery())) {
+                    if (relative.getQuery() != null) {
                         target[3] = relative.getQuery();
 
                     } else {
@@ -175,7 +175,7 @@ private static final String[] resolveAsComponents(final URI base, final URI rela
      */
     private static final String removeDotSegments(final String path) {
 
-        if (UriUtils.isNotDefined(path)) {
+        if (path == null) {
             return null;
         }
 
@@ -244,7 +244,7 @@ private static final String removeDotSegments(final String path) {
      */
     private static final String merge(String basePath, String path) {
 
-        if (UriUtils.isNotDefined(basePath)) {
+        if (basePath == null) {
             return "/".concat(path);
         }
 
diff --git a/src/main/java/com/apicatalog/jsonld/uri/UriUtils.java b/src/main/java/com/apicatalog/jsonld/uri/UriUtils.java
index 0c9d2f3d..851a3701 100644
--- a/src/main/java/com/apicatalog/jsonld/uri/UriUtils.java
+++ b/src/main/java/com/apicatalog/jsonld/uri/UriUtils.java
@@ -164,7 +164,7 @@ protected static final String recompose(final String scheme, final String author
 
         final StringBuilder builder = new StringBuilder();
 
-        if (isDefined(scheme)) {
+        if (scheme != null) {
             builder.append(scheme);
             builder.append(":");
         }
@@ -172,26 +172,17 @@ protected static final String recompose(final String scheme, final String author
             builder.append("//");
             builder.append(authority);
         }
-        if (isDefined(path)) {
+        if (path != null) {
             builder.append(path);
         }
-        if (isDefined(query)) {
+        if (query != null) {
             builder.append('?');
             builder.append(query);
         }
-        if (isDefined(fragment)) {
+        if (fragment != null) {
             builder.append('#');
             builder.append(fragment);
         }
         return builder.toString();
     }
-
-    protected static final boolean isDefined(final String value) {
-        return value != null && StringUtils.isNotBlank(value);
-    }
-
-    protected static final boolean isNotDefined(final String value) {
-        return value == null || StringUtils.isBlank(value);
-    }
-
 }
diff --git a/src/test/resources/com/apicatalog/jsonld/test/issue310-in.json b/src/test/resources/com/apicatalog/jsonld/test/issue310-in.json
new file mode 100644
index 00000000..53f95a22
--- /dev/null
+++ b/src/test/resources/com/apicatalog/jsonld/test/issue310-in.json
@@ -0,0 +1,10 @@
+{
+  "@context": {
+    "@version": 1.1,
+    "@base": "http://example/document",
+    "@vocab": "#"
+  },
+  "@id": "http://example.org/places#BrewEats",
+  "@type": "Restaurant",
+  "name": "Brew Eats"
+}
\ No newline at end of file
diff --git a/src/test/resources/com/apicatalog/jsonld/test/issue310-out.json b/src/test/resources/com/apicatalog/jsonld/test/issue310-out.json
new file mode 100644
index 00000000..f60c7da0
--- /dev/null
+++ b/src/test/resources/com/apicatalog/jsonld/test/issue310-out.json
@@ -0,0 +1,13 @@
+[
+  {
+    "@id": "http://example.org/places#BrewEats",
+    "@type": [
+      "http://example/document#Restaurant"
+    ],
+    "http://example/document#name": [
+      {
+        "@value": "Brew Eats"
+      }
+    ]
+  }
+]
\ No newline at end of file
diff --git a/src/test/resources/com/apicatalog/jsonld/test/manifest.json b/src/test/resources/com/apicatalog/jsonld/test/manifest.json
index 723080ee..6b0e2845 100644
--- a/src/test/resources/com/apicatalog/jsonld/test/manifest.json
+++ b/src/test/resources/com/apicatalog/jsonld/test/manifest.json
@@ -139,6 +139,13 @@
       "expect": "issue257-2-out.json",
       "frame": "issue257-2-frame.json",
       "option": { "omitGraph" : false }
+    },
+    {
+      "@id": "#t0017",
+      "@type": ["jld:PositiveEvaluationTest", "jld:ExpandTest"],
+      "name": "Issue #310: # as vocabulary mapping",
+      "input": "issue310-in.json",
+      "expect": "issue310-out.json"
     }
   ]
 }