diff --git a/src/Base/Quantity.cpp b/src/Base/Quantity.cpp
index 0c9acf129..29e6e4bfb 100644
--- a/src/Base/Quantity.cpp
+++ b/src/Base/Quantity.cpp
@@ -24,6 +24,7 @@
 #ifndef _PreComp_
 #endif
 
+#include <cmath>
 #include "Quantity.h"
 #include "Exception.h"
 
@@ -101,7 +102,7 @@ Quantity& Quantity::operator = (const Quantity &New)
 
 // include the Scanner and the Parser for the Quantitys
 
-Quantity ScanResult;
+Quantity QuantResult;
 
 #ifndef  DOUBLE_MAX
 # define DOUBLE_MAX 1.7976931348623157E+308    /* max decimal value of a "double"*/
@@ -144,13 +145,13 @@ Quantity Quantity::parse(const char* buffer)
     // parse from buffer
     QuantityParser::YY_BUFFER_STATE my_string_buffer = QuantityParser::yy_scan_string (buffer);
     // set the global return variables
-    ScanResult = Quantity(DOUBLE_MIN);
+    QuantResult = Quantity(DOUBLE_MIN);
     // run the parser
     QuantityParser::yyparse ();
     // free the scan buffer
     QuantityParser::yy_delete_buffer (my_string_buffer);
 
-    if (ScanResult == Quantity(DOUBLE_MIN))
+    if (QuantResult == Quantity(DOUBLE_MIN))
         throw Base::Exception("Unknown error in Quantity expression");
-    return ScanResult;
+    return QuantResult;
 }
diff --git a/src/Base/QuantityParser.c b/src/Base/QuantityParser.c
index db70da22d..0410baa6c 100644
--- a/src/Base/QuantityParser.c
+++ b/src/Base/QuantityParser.c
@@ -1322,7 +1322,7 @@ yyreduce:
 
 /* Line 1455 of yacc.c  */
 #line 25 "QuantityParser.y"
-    { ScanResult = (yyvsp[(1) - (1)])     ;    ;}
+    { QuantResult = (yyvsp[(1) - (1)])     ;    ;}
     break;
 
   case 3:
diff --git a/src/Base/QuantityParser.y b/src/Base/QuantityParser.y
index 146e06605..5ab6b1723 100644
--- a/src/Base/QuantityParser.y
+++ b/src/Base/QuantityParser.y
@@ -22,7 +22,7 @@
 
 %%
 
-    input:     exp                			{ ScanResult = $1     ;    }
+    input:     exp                			{ QuantResult = $1     ;    }
  ;     
      
      exp:      NUM                			{ $$ = $1;         	}
diff --git a/src/Base/Unit.h b/src/Base/Unit.h
index e2c416cb4..8c1f92701 100644
--- a/src/Base/Unit.h
+++ b/src/Base/Unit.h
@@ -29,6 +29,7 @@
 #else
 #  include <stdint.h>
 #endif
+#include <string>
 
 namespace Base {
 
@@ -60,8 +61,8 @@ public:
 
     /** Operators. */
     //@{
-    Unit& operator *=(const Unit&that) const {return *this * that;}
-    Unit& operator /=(const Unit&that) const {return *this / that;}
+    inline Unit& operator *=(const Unit& that);
+    inline Unit& operator /=(const Unit& that);
     Unit operator *(const Unit&) const;
     Unit operator /(const Unit&) const;
     bool operator ==(const Unit&) const;
@@ -77,6 +78,18 @@ protected:
     UnitSignature Sig;
 };
 
+inline Unit& Unit::operator *=(const Unit& that)
+{
+    *this = *this * that;
+    return *this;
+}
+
+inline Unit& Unit::operator /=(const Unit& that)
+{
+    *this = *this / that;
+    return *this;
+}
+
 } // namespace Base
 
 #endif // BASE_Unit_H