diff --git a/include/epanet2.bas b/include/epanet2.bas
index 0826a3b..615f045 100644
--- a/include/epanet2.bas
+++ b/include/epanet2.bas
@@ -154,6 +154,13 @@ Public Const EN_INITFLOW = 10    ' Re-initialize flow flag
 Public Const EN_CONST_HP = 0      ' constant horsepower
 Public Const EN_POWER_FUNC = 1    ' power function
 Public Const EN_CUSTOM = 2        ' user-defined custom curve
+Public Const EN_NOCURVE = 3       ' no curve
+
+Public Const EN_V_CURVE = 0       ' volume curve
+Public Const EN_P_CURVE = 1       ' pump curve
+Public Const EN_E_CURVE = 2       ' efficiency curve
+Public Const EN_H_CURVE = 3       ' head loss curve
+Public Const EN_G_CURVE = 4       ' General\default curve
 
 'These are the external functions that comprise the DLL
 
diff --git a/include/epanet2.h b/include/epanet2.h
index 81b469e..b41ae0f 100644
--- a/include/epanet2.h
+++ b/include/epanet2.h
@@ -224,8 +224,6 @@ typedef enum {
   EN_TIMEOFDAY   = 3
 } EN_ControlType;
 
-
-
 typedef enum {
   EN_AVERAGE     = 1,   /* Time statistic types.    */
   EN_MINIMUM     = 2,   /* See TstatType in TYPES.H */
@@ -233,8 +231,6 @@ typedef enum {
   EN_RANGE       = 4
 } EN_StatisticType;
 
-
-
 typedef enum {
   EN_MIX1        = 0,   /* Tank mixing models */
   EN_MIX2        = 1,
@@ -242,8 +238,6 @@ typedef enum {
   EN_LIFO        = 3
 } EN_MixingModel;
 
-
-
 typedef enum {
   EN_NOSAVE        = 0,
   EN_SAVE          = 1,
@@ -251,8 +245,6 @@ typedef enum {
   EN_SAVE_AND_INIT = 11
 } EN_SaveOption;
 
-
-
 typedef enum {
   EN_CONST_HP    = 0,   /* constant horsepower       */
   EN_POWER_FUNC  = 1,   /* power function            */
@@ -260,6 +252,13 @@ typedef enum {
 } EN_CurveType;
 
 
+typedef enum {
+  EN_V_CURVE     = 0,   /*    volume curve                      */
+  EN_P_CURVE     = 1,   /*    pump curve                        */
+  EN_E_CURVE     = 2,   /*    efficiency curve                  */
+  EN_H_CURVE     = 3,   /*    head loss curve                   */
+  EN_G_CURVE     = 4    /*    General\default curve             */
+} EN_CurveType;
 
 // --- Declare the EPANET toolkit functions
 #if defined(__cplusplus)
diff --git a/src/epanet.c b/src/epanet.c
index f0f0ff8..72f59d8 100644
--- a/src/epanet.c
+++ b/src/epanet.c
@@ -2933,7 +2933,7 @@ int DLLEXPORT EN_addcurve(EN_Project *p, char *id) {
 
   strcpy(tmpCur[n].ID, id);
   tmpCur[n].Npts = 1;
-  tmpCur[n].Type = -1;
+  tmpCur[n].Type = G_CURVE;
   tmpCur[n].X = (double *)calloc(tmpCur[n].Npts, sizeof(double));
   tmpCur[n].Y = (double *)calloc(tmpCur[n].Npts, sizeof(double));
   if (tmpCur[n].X == NULL)
@@ -2974,9 +2974,7 @@ int DLLEXPORT EN_addcurve(EN_Project *p, char *id) {
 int DLLEXPORT EN_setcurve(EN_Project *p, int index, EN_API_FLOAT_TYPE *x, EN_API_FLOAT_TYPE *y, int n) {
   
   EN_Network *net = &p->network;  
-  Scurve *Curve = net->Curve;
-  
-  
+  Scurve *Curve = net->Curve;  
   int j;
 
   /* Check for valid arguments */
@@ -3007,12 +3005,9 @@ int DLLEXPORT EN_setcurve(EN_Project *p, int index, EN_API_FLOAT_TYPE *x, EN_API
 int DLLEXPORT EN_setcurvevalue(EN_Project *p, int index, int pnt, EN_API_FLOAT_TYPE x, EN_API_FLOAT_TYPE y) {
   
   EN_Network *net = &p->network;
-  
   Scurve *Curve = net->Curve;
-  
   const int Ncurves = net->Ncurves;
   
-  
   if (!p->Openflag)
     return (102);
   if (index <= 0 || index > Ncurves)
@@ -3713,7 +3708,7 @@ int allocdata(EN_Project *p)
     }
     for (n = 0; n <= par->MaxCurves; n++) {
       net->Curve[n].Npts = 0;
-      net->Curve[n].Type = -1;
+      net->Curve[n].Type = G_CURVE;
       net->Curve[n].X = NULL;
       net->Curve[n].Y = NULL;
     }
diff --git a/src/types.h b/src/types.h
index a039d8c..be6e6fa 100755
--- a/src/types.h
+++ b/src/types.h
@@ -151,8 +151,9 @@ typedef enum {
   V_CURVE,       /*    volume curve                      */
   P_CURVE,       /*    pump curve                        */
   E_CURVE,       /*    efficiency curve                  */
-  H_CURVE
-} CurveType;     /*    head loss curve                   */
+  H_CURVE,       /*    head loss curve                   */
+  G_CURVE        /*    General\default curve             */
+} CurveType;
 
 typedef enum {
   CONST_HP,      /*    constant horsepower              */