diff --git a/ClosedXML/Excel/CalcEngine/CalcEngine.cs b/ClosedXML/Excel/CalcEngine/CalcEngine.cs
index 4a5c347..8cc752e 100644
--- a/ClosedXML/Excel/CalcEngine/CalcEngine.cs
+++ b/ClosedXML/Excel/CalcEngine/CalcEngine.cs
@@ -77,9 +77,11 @@
 
             // skip leading equals sign
             if (_len > 0 && _expr[0] == '=')
-            {
                 _ptr++;
-            }
+
+            // skip leading +'s
+            while (_len > _ptr && _expr[_ptr] == '+')
+                _ptr++;
 
             // parse the expression
             var expr = ParseExpression();
diff --git a/ClosedXML_Tests/Excel/Misc/FormulaTests.cs b/ClosedXML_Tests/Excel/Misc/FormulaTests.cs
index 8d2d470..16ac2a1 100644
--- a/ClosedXML_Tests/Excel/Misc/FormulaTests.cs
+++ b/ClosedXML_Tests/Excel/Misc/FormulaTests.cs
@@ -156,5 +156,22 @@
                 Assert.AreEqual(6, actual);
             }
         }
+
+        [Test]
+        public void FormulaThatStartsWithEqualsAndPlus()
+        {
+            object actual;
+            actual = XLWorkbook.EvaluateExpr("=MID(\"This is a test\", 6, 2)");
+            Assert.AreEqual("is", actual);
+
+            actual = XLWorkbook.EvaluateExpr("=+MID(\"This is a test\", 6, 2)");
+            Assert.AreEqual("is", actual);
+
+            actual = XLWorkbook.EvaluateExpr("=+++++MID(\"This is a test\", 6, 2)");
+            Assert.AreEqual("is", actual);
+
+            actual = XLWorkbook.EvaluateExpr("+MID(\"This is a test\", 6, 2)");
+            Assert.AreEqual("is", actual);
+        }
     }
 }