diff --git a/src/compiler/translator/HashNames.cpp b/src/compiler/translator/HashNames.cpp
index 62b4f6d063..4550760e1a 100644
--- a/src/compiler/translator/HashNames.cpp
+++ b/src/compiler/translator/HashNames.cpp
@@ -76,6 +76,24 @@ ImmutableString HashName(const ImmutableString &name,
 
     // Has a hash function
     ImmutableString hashedName = HashName(name, hashFunction);
+    // The hash function is not collision-resistant. If a different source
+    // identifier already hashed to the same value, disambiguate by appending
+    // the original name so two distinct symbols can never share an emitted
+    // name. (A 64-bit birthday collision is feasible offline in ~2^32 work,
+    // and a collision lets web content alias differently-typed/-sized
+    // declarations after translation.)
+    if (nameMap)
+    {
+        for (const auto &it : *nameMap)
+        {
+            if (it.second == hashedName.data() && it.first != name.data())
+            {
+                hashedName =
+                    BuildConcatenatedImmutableString(hashedName, '_', name);
+                break;
+            }
+        }
+    }
     AddToNameMapIfNotMapped(name, hashedName, nameMap);
     return hashedName;
 }