diff --git a/src/CompletionProvider.php b/src/CompletionProvider.php
index cd78e61..4c42ff4 100644
--- a/src/CompletionProvider.php
+++ b/src/CompletionProvider.php
@@ -247,7 +247,8 @@ class CompletionProvider
 
             foreach ($this->index->getDefinitions() as $fqn => $def) {
                 $fqnStartsWithPrefix = strStartsWith($fqn, $prefix);
-                if (($def->canBeInstantiated || ($def->isGlobal && !isset($creation))) && strStartsWith($fqn, $prefix)) {
+                $fqnContainsPrefix = empty($prefix) || strpos($fqn, $prefix) !== false;
+                if (($def->canBeInstantiated || ($def->isGlobal && !isset($creation))) && $fqnContainsPrefix) {
                     if ($namespaceDefinition !== null && $namespaceDefinition->name !== null) {
                         $namespacePrefix = (string)Tolerant\ResolvedName::buildName($namespaceDefinition->name->nameParts, $node->getFileContents());
 
@@ -306,7 +307,7 @@ class CompletionProvider
             }
         }
 
-       return $list;
+        return $list;
     }
 
     /**
diff --git a/tests/Server/TextDocument/CompletionTest.php b/tests/Server/TextDocument/CompletionTest.php
index 20743de..e8b417d 100644
--- a/tests/Server/TextDocument/CompletionTest.php
+++ b/tests/Server/TextDocument/CompletionTest.php
@@ -53,7 +53,7 @@ class CompletionTest extends TestCase
             new TextDocumentIdentifier($completionUri),
             new Position(3, 7)
         )->wait();
-        $this->assertEquals(new CompletionList([
+        $this->assertCompletionsListSubset(new CompletionList([
             new CompletionItem(
                 'testProperty',
                 CompletionItemKind::PROPERTY,
@@ -77,7 +77,7 @@ class CompletionTest extends TestCase
             new TextDocumentIdentifier($completionUri),
             new Position(3, 6)
         )->wait();
-        $this->assertEquals(new CompletionList([
+        $this->assertCompletionsListSubset(new CompletionList([
             new CompletionItem(
                 'testProperty',
                 CompletionItemKind::PROPERTY,
@@ -101,7 +101,7 @@ class CompletionTest extends TestCase
             new TextDocumentIdentifier($completionUri),
             new Position(8, 5)
         )->wait();
-        $this->assertEquals(new CompletionList([
+        $this->assertCompletionsListSubset(new CompletionList([
             new CompletionItem(
                 '$var',
                 CompletionItemKind::VARIABLE,
@@ -133,7 +133,7 @@ class CompletionTest extends TestCase
             new TextDocumentIdentifier($completionUri),
             new Position(8, 6)
         )->wait();
-        $this->assertEquals(new CompletionList([
+        $this->assertCompletionsListSubset(new CompletionList([
             new CompletionItem(
                 '$param',
                 CompletionItemKind::VARIABLE,
@@ -155,7 +155,7 @@ class CompletionTest extends TestCase
             new TextDocumentIdentifier($completionUri),
             new Position(6, 10)
         )->wait();
-        $this->assertEquals(new CompletionList([
+        $this->assertCompletionsListSubset(new CompletionList([
             // Global TestClass definition (inserted as \TestClass)
             new CompletionItem(
                 'TestClass',
@@ -205,7 +205,7 @@ class CompletionTest extends TestCase
             new TextDocumentIdentifier($completionUri),
             new Position(6, 5)
         )->wait();
-        $this->assertEquals(new CompletionList([
+        $this->assertCompletionsListSubset(new CompletionList([
             new CompletionItem(
                 'TestClass',
                 CompletionItemKind::CLASS_,
@@ -226,7 +226,7 @@ class CompletionTest extends TestCase
             new TextDocumentIdentifier($completionUri),
             new Position(2, 14)
         )->wait();
-        $this->assertEquals(new CompletionList([
+        $this->assertCompletionsListSubset(new CompletionList([
             new CompletionItem(
                 'staticTestProperty',
                 CompletionItemKind::PROPERTY,
@@ -247,7 +247,7 @@ class CompletionTest extends TestCase
             new TextDocumentIdentifier($completionUri),
             new Position(2, 11)
         )->wait();
-        $this->assertEquals(new CompletionList([
+        $this->assertCompletionsListSubset(new CompletionList([
             new CompletionItem(
                 'TEST_CLASS_CONST',
                 CompletionItemKind::VARIABLE,
@@ -280,7 +280,7 @@ class CompletionTest extends TestCase
             new TextDocumentIdentifier($completionUri),
             new Position(2, 13)
         )->wait();
-        $this->assertEquals(new CompletionList([
+        $this->assertCompletionsListSubset(new CompletionList([
             new CompletionItem(
                 'TEST_CLASS_CONST',
                 CompletionItemKind::VARIABLE,
@@ -313,7 +313,7 @@ class CompletionTest extends TestCase
             new TextDocumentIdentifier($completionUri),
             new Position(2, 13)
         )->wait();
-        $this->assertEquals(new CompletionList([
+        $this->assertCompletionsListSubset(new CompletionList([
             new CompletionItem(
                 'TEST_CLASS_CONST',
                 CompletionItemKind::VARIABLE,
@@ -346,7 +346,7 @@ class CompletionTest extends TestCase
             new TextDocumentIdentifier($completionUri),
             new Position(6, 6)
         )->wait();
-        $this->assertEquals(new CompletionList([
+        $this->assertCompletionsListSubset(new CompletionList([
             new CompletionItem(
                 'TestClass',
                 CompletionItemKind::CLASS_,
@@ -367,7 +367,7 @@ class CompletionTest extends TestCase
             new TextDocumentIdentifier($completionUri),
             new Position(2, 1)
         )->wait();
-        $this->assertEquals(new CompletionList([
+        $this->assertCompletionsListSubset(new CompletionList([
             new CompletionItem('class', CompletionItemKind::KEYWORD, null, null, null, null, 'class '),
             new CompletionItem('clone', CompletionItemKind::KEYWORD, null, null, null, null, 'clone ')
         ], true), $items);
@@ -381,7 +381,7 @@ class CompletionTest extends TestCase
             new TextDocumentIdentifier($completionUri),
             new Position(0, 0)
         )->wait();
-        $this->assertEquals(new CompletionList([
+        $this->assertCompletionsListSubset(new CompletionList([
             new CompletionItem(
                 '<?php',
                 CompletionItemKind::KEYWORD,
@@ -403,7 +403,7 @@ class CompletionTest extends TestCase
             new TextDocumentIdentifier($completionUri),
             new Position(0, 1)
         )->wait();
-        $this->assertEquals(new CompletionList([
+        $this->assertCompletionsListSubset(new CompletionList([
             new CompletionItem(
                 '<?php',
                 CompletionItemKind::KEYWORD,
@@ -425,7 +425,7 @@ class CompletionTest extends TestCase
             new TextDocumentIdentifier($completionUri),
             new Position(4, 6)
         )->wait();
-        $this->assertEquals(new CompletionList([
+        $this->assertCompletionsListSubset(new CompletionList([
             new CompletionItem(
                 'SomeNamespace',
                 CompletionItemKind::MODULE,
@@ -446,7 +446,7 @@ class CompletionTest extends TestCase
             new TextDocumentIdentifier($completionUri),
             new Position(4, 8)
         )->wait();
-        $this->assertEquals(new CompletionList([
+        $this->assertCompletionsListSubset(new CompletionList([
             new CompletionItem(
                 '$abc2',
                 CompletionItemKind::VARIABLE,
@@ -469,4 +469,12 @@ class CompletionTest extends TestCase
             )
         ], true), $items);
     }
+
+    private function assertCompletionsListSubset(CompletionList $subsetList, CompletionList $list) {
+        foreach ($subsetList->items as $expectedItem) {
+            $this->assertContains($expectedItem, $list->items, null, null, false);
+        }
+
+        $this->assertEquals($subsetList->isIncomplete, $list->isIncomplete);
+    }
 }