diff --git a/lib/checkuninitvar.cpp b/lib/checkuninitvar.cpp
index ea7ed6391..309d146ae 100644
--- a/lib/checkuninitvar.cpp
+++ b/lib/checkuninitvar.cpp
@@ -1783,8 +1783,19 @@ bool CheckUninitVar::isVariableUsage(const Token *vartok, bool pointer, bool all
 
     if (Token::Match(vartok->previous(), "++|--|%cop%")) {
         if (_tokenizer->isCPP() && Token::Match(vartok->previous(), ">>|<<")) {
-            if (Token::Match(vartok->previous()->astOperand1(), ">>|<<"))
-                return false; // Looks like stream operator
+            const Token* tok2 = vartok->previous();
+            if (Token::simpleMatch(tok2->astOperand1(), ">>"))
+                return false; // Looks like stream operator, initializes the variable
+            if (Token::simpleMatch(tok2, "<<")) {
+                // Looks like stream operator, but could also initialize the variable. Check lhs.
+                do {
+                    tok2 = tok2->astOperand1();
+                } while (Token::simpleMatch(tok2, "<<"));
+                if (tok2->strAt(-1) == "::")
+                    tok2 = tok2->previous();
+                if (tok2 && (Token::simpleMatch(tok2->previous(), "std ::") || (tok2->variable() && tok2->variable()->isStlType()) || tok2->isStandardType()))
+                    return true;
+            }
             const Variable *var = vartok->tokAt(-2)->variable();
             return (var && var->typeStartToken()->isStandardType());
         }
diff --git a/test/testuninitvar.cpp b/test/testuninitvar.cpp
index 500c8d6b6..663178a62 100644
--- a/test/testuninitvar.cpp
+++ b/test/testuninitvar.cpp
@@ -443,6 +443,19 @@ private:
                             "}");
             ASSERT_EQUALS("", errout.str());
 
+            checkUninitVarB("void f(int b) {\n"
+                            "    int a;\n"
+                            "    std::cin >> b >> a;\n"
+                            "    return a;"
+                            "}");
+            ASSERT_EQUALS("", errout.str());
+
+            checkUninitVar2("void f(int i) {\n"
+                            "    int a;\n"
+                            "    i >> a;\n"
+                            "}");
+            ASSERT_EQUALS("[test.cpp:3]: (error) Uninitialized variable: a\n", errout.str());
+
             checkUninitVar("int a() {\n"
                            "    int ret;\n"
                            "    int a = value >> ret;\n"
@@ -480,6 +493,31 @@ private:
                             "    return a;\n"
                             "}");
             ASSERT_EQUALS("", errout.str());
+
+            // #4673
+            checkUninitVar2("void f() {\n"
+                            "    int a;\n"
+                            "    std::cout << a;\n"
+                            "}");
+            ASSERT_EQUALS("[test.cpp:3]: (error) Uninitialized variable: a\n", errout.str());
+
+            checkUninitVar2("void f(std::ostringstream& os) {\n"
+                            "    int a;\n"
+                            "    os << a;\n"
+                            "}");
+            ASSERT_EQUALS("[test.cpp:3]: (error) Uninitialized variable: a\n", errout.str());
+
+            checkUninitVar2("void f() {\n"
+                            "    int a;\n"
+                            "    std::cout << 1 << a;\n"
+                            "}");
+            ASSERT_EQUALS("[test.cpp:3]: (error) Uninitialized variable: a\n", errout.str());
+
+            checkUninitVar2("void f(std::ostringstream& os) {\n"
+                            "    int a;\n"
+                            "    os << 1 << a;\n"
+                            "}");
+            ASSERT_EQUALS("[test.cpp:3]: (error) Uninitialized variable: a\n", errout.str());
         }
 
         checkUninitVarB("void a() {\n"   // asm