diff --git a/lib/mathlib.cpp b/lib/mathlib.cpp
index 2d5555b34..6b07df126 100644
--- a/lib/mathlib.cpp
+++ b/lib/mathlib.cpp
@@ -116,7 +116,7 @@ bool MathLib::isHex(const std::string& str)
 bool MathLib::isBin(const std::string& str)
 {
     bool sign = str[0]=='-' || str[0]=='+';
-    return(str.compare(sign?1:0, 2, "0b") == 0 && str.find_first_not_of("10b", 1) == std::string::npos);
+    return((str.compare(sign?1:0, 2, "0b") == 0 || str.compare(sign?1:0, 2, "0B") == 0) && str.find_first_not_of("10bB", 1) == std::string::npos);
 }
 
 bool MathLib::isInt(const std::string & s)
diff --git a/test/testmathlib.cpp b/test/testmathlib.cpp
index 3a8ba9022..5a91aff38 100644
--- a/test/testmathlib.cpp
+++ b/test/testmathlib.cpp
@@ -171,6 +171,7 @@ private:
         ASSERT_EQUALS(-1 	, MathLib::toLongNumber("-0b1"));
         ASSERT_EQUALS(215 	, MathLib::toLongNumber("0b11010111"));
         ASSERT_EQUALS(-215 	, MathLib::toLongNumber("-0b11010111"));
+        ASSERT_EQUALS(215 	, MathLib::toLongNumber("0B11010111"));
 
         // from base 10
         ASSERT_EQUALS(10	, MathLib::toLongNumber("10"));