diff --git a/modules/juce_audio_basics/buffers/juce_AudioDataConverters.cpp b/modules/juce_audio_basics/buffers/juce_AudioDataConverters.cpp
index a2a033ef9c..196d50b226 100644
--- a/modules/juce_audio_basics/buffers/juce_AudioDataConverters.cpp
+++ b/modules/juce_audio_basics/buffers/juce_AudioDataConverters.cpp
@@ -579,7 +579,7 @@ public:
         }
     };
 
-    void runTest()
+    void runTest() override
     {
         Random r = getRandom();
         beginTest ("Round-trip conversion: Int8");
diff --git a/modules/juce_audio_basics/buffers/juce_FloatVectorOperations.cpp b/modules/juce_audio_basics/buffers/juce_FloatVectorOperations.cpp
index 971ff65421..20fc28301b 100644
--- a/modules/juce_audio_basics/buffers/juce_FloatVectorOperations.cpp
+++ b/modules/juce_audio_basics/buffers/juce_FloatVectorOperations.cpp
@@ -1146,7 +1146,7 @@ public:
         }
     };
 
-    void runTest()
+    void runTest() override
     {
         beginTest ("FloatVectorOperations");
 
diff --git a/modules/juce_core/containers/juce_AbstractFifo.cpp b/modules/juce_core/containers/juce_AbstractFifo.cpp
index d9db76c8f0..d608fcd1f4 100644
--- a/modules/juce_core/containers/juce_AbstractFifo.cpp
+++ b/modules/juce_core/containers/juce_AbstractFifo.cpp
@@ -183,7 +183,7 @@ public:
         Random random;
     };
 
-    void runTest()
+    void runTest() override
     {
         beginTest ("AbstractFifo");
 
diff --git a/modules/juce_core/files/juce_File.cpp b/modules/juce_core/files/juce_File.cpp
index 1b4687e8ef..87b9fb46f5 100644
--- a/modules/juce_core/files/juce_File.cpp
+++ b/modules/juce_core/files/juce_File.cpp
@@ -908,7 +908,7 @@ class FileTests  : public UnitTest
 public:
     FileTests() : UnitTest ("Files") {}
 
-    void runTest()
+    void runTest() override
     {
         beginTest ("Reading");
 
diff --git a/modules/juce_core/javascript/juce_JSON.cpp b/modules/juce_core/javascript/juce_JSON.cpp
index 9dbd415491..9f7eca708d 100644
--- a/modules/juce_core/javascript/juce_JSON.cpp
+++ b/modules/juce_core/javascript/juce_JSON.cpp
@@ -607,7 +607,7 @@ public:
         }
     }
 
-    void runTest()
+    void runTest() override
     {
         beginTest ("JSON");
         Random r = getRandom();
diff --git a/modules/juce_core/maths/juce_Random.cpp b/modules/juce_core/maths/juce_Random.cpp
index c0a3aafbea..cb1156283f 100644
--- a/modules/juce_core/maths/juce_Random.cpp
+++ b/modules/juce_core/maths/juce_Random.cpp
@@ -162,7 +162,7 @@ class RandomTests  : public UnitTest
 public:
     RandomTests() : UnitTest ("Random") {}
 
-    void runTest()
+    void runTest() override
     {
         beginTest ("Random");
 
diff --git a/modules/juce_core/streams/juce_MemoryInputStream.cpp b/modules/juce_core/streams/juce_MemoryInputStream.cpp
index 2621e4f717..da94088bc4 100644
--- a/modules/juce_core/streams/juce_MemoryInputStream.cpp
+++ b/modules/juce_core/streams/juce_MemoryInputStream.cpp
@@ -101,7 +101,7 @@ class MemoryStreamTests  : public UnitTest
 public:
     MemoryStreamTests() : UnitTest ("MemoryInputStream & MemoryOutputStream") {}
 
-    void runTest()
+    void runTest() override
     {
         beginTest ("Basics");
         Random r = getRandom();
diff --git a/modules/juce_core/text/juce_Base64.cpp b/modules/juce_core/text/juce_Base64.cpp
index 101a5e1659..6c1586a460 100644
--- a/modules/juce_core/text/juce_Base64.cpp
+++ b/modules/juce_core/text/juce_Base64.cpp
@@ -142,7 +142,7 @@ public:
         return m.getMemoryBlock();
     }
 
-    void runTest()
+    void runTest() override
     {
         beginTest ("Base64");
 
diff --git a/modules/juce_core/text/juce_String.cpp b/modules/juce_core/text/juce_String.cpp
index ec82e547d4..cf9336d726 100644
--- a/modules/juce_core/text/juce_String.cpp
+++ b/modules/juce_core/text/juce_String.cpp
@@ -2224,7 +2224,7 @@ public:
         return CharPointer_UTF32 (buffer);
     }
 
-    void runTest()
+    void runTest() override
     {
         Random r = getRandom();
 
diff --git a/modules/juce_core/text/juce_TextDiff.cpp b/modules/juce_core/text/juce_TextDiff.cpp
index 0ec44f0757..4b07015b2b 100644
--- a/modules/juce_core/text/juce_TextDiff.cpp
+++ b/modules/juce_core/text/juce_TextDiff.cpp
@@ -242,7 +242,7 @@ public:
         expectEquals (result, b);
     }
 
-    void runTest()
+    void runTest() override
     {
         beginTest ("TextDiff");
 
diff --git a/modules/juce_core/threads/juce_ChildProcess.cpp b/modules/juce_core/threads/juce_ChildProcess.cpp
index 916c03b4a3..9fd758cd16 100644
--- a/modules/juce_core/threads/juce_ChildProcess.cpp
+++ b/modules/juce_core/threads/juce_ChildProcess.cpp
@@ -89,7 +89,7 @@ class ChildProcessTests  : public UnitTest
 public:
     ChildProcessTests() : UnitTest ("ChildProcess") {}
 
-    void runTest()
+    void runTest() override
     {
         beginTest ("Child Processes");
 
diff --git a/modules/juce_core/threads/juce_Thread.cpp b/modules/juce_core/threads/juce_Thread.cpp
index 6189ca5f80..dce488dbc0 100644
--- a/modules/juce_core/threads/juce_Thread.cpp
+++ b/modules/juce_core/threads/juce_Thread.cpp
@@ -273,7 +273,7 @@ class AtomicTests  : public UnitTest
 public:
     AtomicTests() : UnitTest ("Atomics") {}
 
-    void runTest()
+    void runTest() override
     {
         beginTest ("Misc");
 
diff --git a/modules/juce_core/unit_tests/juce_UnitTest.h b/modules/juce_core/unit_tests/juce_UnitTest.h
index 02ad9f9225..1c80b4eddd 100644
--- a/modules/juce_core/unit_tests/juce_UnitTest.h
+++ b/modules/juce_core/unit_tests/juce_UnitTest.h
@@ -44,7 +44,7 @@ class UnitTestRunner;
     public:
         MyTest()  : UnitTest ("Foobar testing") {}
 
-        void runTest()
+        void runTest() override
         {
             beginTest ("Part 1");
 
diff --git a/modules/juce_core/zip/juce_GZIPCompressorOutputStream.cpp b/modules/juce_core/zip/juce_GZIPCompressorOutputStream.cpp
index f1db2b43fd..a808ab8024 100644
--- a/modules/juce_core/zip/juce_GZIPCompressorOutputStream.cpp
+++ b/modules/juce_core/zip/juce_GZIPCompressorOutputStream.cpp
@@ -166,7 +166,7 @@ class GZIPTests  : public UnitTest
 public:
     GZIPTests()   : UnitTest ("GZIP") {}
 
-    void runTest()
+    void runTest() override
     {
         beginTest ("GZIP");
         Random rng = getRandom();
diff --git a/modules/juce_cryptography/hashing/juce_MD5.cpp b/modules/juce_cryptography/hashing/juce_MD5.cpp
index b6d397300e..d4d15639e7 100644
--- a/modules/juce_cryptography/hashing/juce_MD5.cpp
+++ b/modules/juce_cryptography/hashing/juce_MD5.cpp
@@ -321,7 +321,7 @@ public:
         }
     }
 
-    void runTest()
+    void runTest() override
     {
         beginTest ("MD5");
 
diff --git a/modules/juce_cryptography/hashing/juce_SHA256.cpp b/modules/juce_cryptography/hashing/juce_SHA256.cpp
index 3fc87bdccd..66c31e1c37 100644
--- a/modules/juce_cryptography/hashing/juce_SHA256.cpp
+++ b/modules/juce_cryptography/hashing/juce_SHA256.cpp
@@ -260,7 +260,7 @@ public:
         }
     }
 
-    void runTest()
+    void runTest() override
     {
         beginTest ("SHA256");
 
diff --git a/modules/juce_cryptography/hashing/juce_Whirlpool.cpp b/modules/juce_cryptography/hashing/juce_Whirlpool.cpp
index 2e36317ad4..c271ae5781 100644
--- a/modules/juce_cryptography/hashing/juce_Whirlpool.cpp
+++ b/modules/juce_cryptography/hashing/juce_Whirlpool.cpp
@@ -646,7 +646,7 @@ public:
         }
     }
 
-    void runTest()
+    void runTest() override
     {
         beginTest ("Whirlpool");
 
diff --git a/modules/juce_data_structures/values/juce_ValueTree.cpp b/modules/juce_data_structures/values/juce_ValueTree.cpp
index 1d63817165..e030f19e09 100644
--- a/modules/juce_data_structures/values/juce_ValueTree.cpp
+++ b/modules/juce_data_structures/values/juce_ValueTree.cpp
@@ -1106,7 +1106,7 @@ public:
         return v;
     }
 
-    void runTest()
+    void runTest() override
     {
         beginTest ("ValueTree");
         Random r = getRandom();