diff --git a/test/testmathlib.cpp b/test/testmathlib.cpp
index d8f75f283..d6d33c0bc 100644
--- a/test/testmathlib.cpp
+++ b/test/testmathlib.cpp
@@ -308,7 +308,7 @@ private:
         ASSERT_EQUALS(1714631779, MathLib::toLongNumber("'\\U0001f34c'"));
         {
             // some unit-testing for a utility function
-            ASSERT_EQUALS(0, MathLib::characterLiteralToLongNumber(std::string("")));
+            ASSERT_EQUALS(0, MathLib::characterLiteralToLongNumber(std::string()));
             ASSERT_EQUALS(32, MathLib::characterLiteralToLongNumber(std::string(" ")));
             ASSERT_EQUALS(538976288, MathLib::characterLiteralToLongNumber(std::string("          ")));
             ASSERT_THROW(MathLib::characterLiteralToLongNumber(std::string("\\u")), InternalError);
@@ -700,7 +700,7 @@ private:
         value = "garbage";
         ASSERT_EQUALS(false, MathLib::isValidIntegerSuffix(value.begin(), value.end()));
 
-        value = "";
+        value.clear();
         ASSERT_EQUALS(false, MathLib::isValidIntegerSuffix(value.begin(), value.end()));
 
         value = "llu ";
diff --git a/test/testmemleak.cpp b/test/testmemleak.cpp
index 13bb030f1..b5b5659b0 100644
--- a/test/testmemleak.cpp
+++ b/test/testmemleak.cpp
@@ -2596,7 +2596,7 @@ private:
               "   if ((ret = alloc(&p)) != 0) return;\n"
               "   free(p);\n"
               "}");
-        ASSERT_EQUALS(std::string(""), errout.str());
+        ASSERT_EQUALS(std::string(), errout.str());
     }
 
 
diff --git a/test/testsymboldatabase.cpp b/test/testsymboldatabase.cpp
index d218c5917..69ac5cb3c 100644
--- a/test/testsymboldatabase.cpp
+++ b/test/testsymboldatabase.cpp
@@ -1361,7 +1361,7 @@ private:
                       "    if (pDocSh && !getCellRangesForAddress(nFlags)) ;\n"
                       "}");
 
-        ASSERT(db && errout.str() == "");
+        ASSERT(db && errout.str().empty());
 
         if (db) {
             const Scope *scope = db->findScopeByName("getFormula1");
@@ -1377,7 +1377,7 @@ private:
                       "    if (pDocSh && !getCellRangesForAddress(nFlags)) ;\n"
                       "}");
 
-        ASSERT(db && errout.str() == "");
+        ASSERT(db && errout.str().empty());
 
         if (db) {
             const Scope *scope = db->findScopeByName("getFormula1");
@@ -1397,7 +1397,7 @@ private:
                       "    if (pDocSh && !getCellRangesForAddress(nFlags)) ;\n"
                       "}");
 
-        ASSERT(db && errout.str() == "");
+        ASSERT(db && errout.str().empty());
 
         if (db) {
             const Scope *scope = db->findScopeByName("getFormula1");
@@ -1414,7 +1414,7 @@ private:
                       "extern void f5() { };\n"
                       "void f6() { }");
 
-        ASSERT(db && errout.str() == "");
+        ASSERT(db && errout.str().empty());
 
         if (db) {
             const Token *f = Token::findsimplematch(tokenizer.tokens(), "f1");