diff --git a/IPhreeqc.2012.vcxproj b/IPhreeqc.2012.vcxproj
index 2ea1437f..6e79ee79 100644
--- a/IPhreeqc.2012.vcxproj
+++ b/IPhreeqc.2012.vcxproj
@@ -246,7 +246,7 @@ copy "$(OutDir)$(TargetName)$(TargetExt)" "libx64\$(TargetName)$(TargetExt)"</Co
     <PostBuildEvent>
       <Command>IF NOT EXIST lib mkdir lib
 copy "$(OutDir)$(TargetName)$(TargetExt)" "lib\$(TargetName)$(TargetExt)"
-copy "$(OutDir)vc100.pdb" "lib\vc100.pdb"</Command>
+copy "$(OutDir)vc110.pdb" "lib\vc110.pdb"</Command>
     </PostBuildEvent>
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
diff --git a/src/IPhreeqc.cpp b/src/IPhreeqc.cpp
index 65ad994c..2822fbb8 100644
--- a/src/IPhreeqc.cpp
+++ b/src/IPhreeqc.cpp
@@ -728,7 +728,7 @@ int IPhreeqc::RunString(const char* input)
 	return this->PhreeqcPtr->get_input_errors();
 }
 
-void IPhreeqc::SetBasicCallback(double (*cookie)(double *x1, double *x2, char *str))
+void IPhreeqc::SetBasicCallback(double (*cookie)(double x1, double x2, const char *str))
 {
 	this->PhreeqcPtr->register_basic_callback(cookie);
 }
diff --git a/src/IPhreeqc.h b/src/IPhreeqc.h
index b1f98c63..44f08314 100644
--- a/src/IPhreeqc.h
+++ b/src/IPhreeqc.h
@@ -1535,14 +1535,14 @@ Headings
  *  <PRE>
  *  FUNCTION SetBasicCallback(ID,COOKIE)
  *    INTEGER  :: ID
- *    double (*cookie)(double *x1, double *x2, char *str)
+ *    double (*cookie)(double x1, double x2, const char *str)
  *    INTEGER  :: SetBasicCallback
  *  END FUNCTION SetBasicCallback
  *  </PRE>
  *  </CODE>
  *  @endhtmlonly
  */
-	IPQ_DLL_EXPORT IPQ_RESULT  SetBasicCallback(int id, double (*cookie)(double *x1, double *x2, char *str));
+	IPQ_DLL_EXPORT IPQ_RESULT  SetBasicCallback(int id, double (*cookie)(double x1, double x2, const char *str));
 
 /**
  *  Sets Fortran callback function for the Basic interpreter.  
diff --git a/src/IPhreeqc.hpp b/src/IPhreeqc.hpp
index 9fc2936e..8ca2db4e 100644
--- a/src/IPhreeqc.hpp
+++ b/src/IPhreeqc.hpp
@@ -658,11 +658,11 @@ public:
 	 *  Sets a C callback function for Basic programs. The syntax for the Basic command is
 	 *  10 result = CALLBACK(x1, x2, string$)
 	 *  The syntax for the C function is
-	 *  double my_callback(double x1, double x2, char * string)
+	 *  double my_callback(double x1, double x2, const char * string)
 	 *  @param cookie           The name of a user-defined function 
 	 *  @see                    SetBasicFortranCallback
 	 */
-	void                     SetBasicCallback(double (*cookie)(double *x1, double *x2, char *str));
+	void                     SetBasicCallback(double (*cookie)(double x1, double x2, const char *str));
 
 	/**
 	 *  Sets a Fortran callback function for Basic programs. The syntax for the Basic command is
diff --git a/src/IPhreeqcLib.cpp b/src/IPhreeqcLib.cpp
index 8a209655..4c0f0ec4 100644
--- a/src/IPhreeqcLib.cpp
+++ b/src/IPhreeqcLib.cpp
@@ -715,7 +715,7 @@ RunString(int id, const char* input)
 }
 
 IPQ_RESULT
-SetBasicCallback(int id, double (*cookie)(double *x1, double *x2, char *str))
+SetBasicCallback(int id, double (*cookie)(double x1, double x2, const char *str))
 {
 	IPhreeqc* IPhreeqcPtr = IPhreeqcLib::GetInstance(id);
 	if (IPhreeqcPtr)