diff --git a/lib/astutils.cpp b/lib/astutils.cpp
index 96ba644f3d5..7bf42b5a493 100644
--- a/lib/astutils.cpp
+++ b/lib/astutils.cpp
@@ -3305,6 +3305,7 @@ static ExprUsage getFunctionUsage(const Token* tok, int indirect, const Settings
                         return ExprUsage::PassedByReference;
                     }
                 }
+                return ExprUsage::NotUsed;
             }
         }
         if (!args.empty() && indirect == 0 && !addressOf)
diff --git a/test/testuninitvar.cpp b/test/testuninitvar.cpp
index 215b5167428..3ce6c654036 100644
--- a/test/testuninitvar.cpp
+++ b/test/testuninitvar.cpp
@@ -4345,6 +4345,13 @@ class TestUninitVar : public TestFixture {
                         "  a = item.a;\n"
                         "}", "test.c");
         ASSERT_EQUALS("", errout_str());
+
+        valueFlowUninit("void f(int& r) {}\n" // #12536
+                        "void g() {\n"
+                        "    int i;\n"
+                        "    f(i);\n"
+                        "}");
+        ASSERT_EQUALS("", errout_str());
     }
 
     void uninitStructMember() { // struct members