diff --git a/inst/include/rxode2ptr.h b/inst/include/rxode2ptr.h
index 6821db274..b5b478c57 100644
--- a/inst/include/rxode2ptr.h
+++ b/inst/include/rxode2ptr.h
@@ -164,6 +164,9 @@ extern "C" {
   typedef double * (*getOpIndSolve_t)(rx_solving_options* op, rx_solving_options_ind* ind, int idx);
   extern getOpIndSolve_t getOpIndSolve;
 
+  typedef int (*getRxNpars_t)(rx_solve *rx);
+  extern getRxNpars_t getRxNpars;
+
   static inline SEXP iniRxodePtrs0(SEXP p) {
     if (_rxode2_rxRmvnSEXP_ == NULL) {
       _rxode2_rxRmvnSEXP_ = (_rxode2_rxRmvnSEXP_t) R_ExternalPtrAddrFn(VECTOR_ELT(p, 0));
@@ -214,6 +217,7 @@ extern "C" {
       getRxNobs = (getRxNobs_t) R_ExternalPtrAddrFn(VECTOR_ELT(p, 45));
       getRxNobs2 = (getRxNobs2_t) R_ExternalPtrAddrFn(VECTOR_ELT(p, 46));
       getOpIndSolve = (getOpIndSolve_t) R_ExternalPtrAddrFn(VECTOR_ELT(p, 47));
+      getRxNpars = (getRxNpars_t) R_ExternalPtrAddrFn(VECTOR_ELT(p, 48));
     }
     return R_NilValue;
   }
@@ -267,6 +271,7 @@ extern "C" {
   getRxNobs_t getRxNobs = NULL;                         \
   getRxNobs2_t getRxNobs2 = NULL;                       \
   getOpIndSolve_t getOpIndSolve = NULL;                 \
+  getRxNpars_t getRxNpars = NULL;                       \
   SEXP iniRxodePtrs(SEXP ptr) {                         \
     return iniRxodePtrs0(ptr);                          \
   }                                                     \
diff --git a/src/init.c b/src/init.c
index c73dc2c3f..13982a808 100644
--- a/src/init.c
+++ b/src/init.c
@@ -421,7 +421,7 @@ SEXP _rxode2_rxode2Ptr(void) {
   SEXP rxode2getOpIndSolve = PROTECT(R_MakeExternalPtrFn((DL_FUNC)&getOpIndSolve, R_NilValue, R_NilValue)); pro++;
 
 
-#define nVec 48
+#define nVec 49
 
   SEXP ret = PROTECT(Rf_allocVector(VECSXP, nVec)); pro++;
   SET_VECTOR_ELT(ret, 0, rxode2rxRmvnSEXP);
@@ -472,6 +472,7 @@ SEXP _rxode2_rxode2Ptr(void) {
   SET_VECTOR_ELT(ret, 45, rxode2getRxNobs);
   SET_VECTOR_ELT(ret, 46, rxode2getRxNobs2);
   SET_VECTOR_ELT(ret, 47, rxode2getOpIndSolve);
+  SET_VECTOR_ELT(ret, 48, getRxNpars);
 
   SEXP retN = PROTECT(Rf_allocVector(STRSXP, nVec)); pro++;
   SET_STRING_ELT(retN, 0, Rf_mkChar("rxode2rxRmvnSEXP"));
@@ -522,6 +523,7 @@ SEXP _rxode2_rxode2Ptr(void) {
   SET_STRING_ELT(retN, 45, Rf_mkChar("rxode2getRxNobs"));
   SET_STRING_ELT(retN, 46, Rf_mkChar("rxode2getRxNobs2"));
   SET_STRING_ELT(retN, 47, Rf_mkChar("rxode2getOpIndSolve"));
+  SET_VECTOR_ELT(retN, 48, Rf_mkChar("rxode2getRxNpars"));
 
 #undef nVec
 
diff --git a/src/rx2api.c b/src/rx2api.c
index c59d3f778..f16ec7636 100644
--- a/src/rx2api.c
+++ b/src/rx2api.c
@@ -185,6 +185,10 @@ int getRxNobs(rx_solve *rx) {
 int getRxNobs2(rx_solve *rx) {
   return rx->nobs2;
 }
+
+int getRxNpars(rx_solve *rx) {
+  return rx->npars;
+}
 ////////////////////////////////////////////////////////////////////////
 // Get solve vector for ith solve
 ////////////////////////////////////////////////////////////////////////
diff --git a/src/rx2api.h b/src/rx2api.h
index 4c131cf90..c95208532 100644
--- a/src/rx2api.h
+++ b/src/rx2api.h
@@ -120,6 +120,9 @@ extern "C" {
   // Get the number of observations excluding evid=2
   int getRxNobs2(rx_solve *rx);
 
+  // Get the number of parameters loaded
+  int getRxNpars(rx_solve *rx);
+
   double * getOpIndSolve(rx_solving_options* op, rx_solving_options_ind* ind, int idx);
 
 #if defined(__cplusplus)