diff --git a/.github/workflows/pkgdown.yml b/.github/workflows/pkgdown.yml
index bf58e7a..6e5849f 100644
--- a/.github/workflows/pkgdown.yml
+++ b/.github/workflows/pkgdown.yml
@@ -52,6 +52,8 @@ jobs:
         run: |
           echo "Contents of src/bb-bollinger-bands.cpp:"
           cat src/bb-bollinger-bands.cpp
+          echo "Contents of src/sma-simple-moving-average.cpp:"
+          cat src/sma-simple-moving-average.cpp
           echo "Contents of src/init.c:"
           cat src/init.c
           echo "Compiling C++ code manually:"
@@ -74,4 +76,4 @@ jobs:
       - name: Deploy to branch
         if: success()
         shell: Rscript {0}
-        run: pkgdown::deploy_to_branch(branch = "bot/github-pages")
\ No newline at end of file
+        run: pkgdown::deploy_to_branch(branch = "bot/github-pages")
diff --git a/src/bb-bollinger-bands.cpp b/src/bb-bollinger-bands.cpp
index 8bbacc9..1c1d479 100644
--- a/src/bb-bollinger-bands.cpp
+++ b/src/bb-bollinger-bands.cpp
@@ -1,13 +1,13 @@
 #include <Rcpp.h>
-#include <math.h>
+// [[Rcpp::interfaces(r, cpp)]]
 
-#include "bb-bollinger-bands.h"
+#include <math.h>
 #include "sma-simple-moving-average.h"
 
-using namespace Rcpp;
-
 // https://gallery.rcpp.org/articles/creating-a-datatable-in-rcpp/
 
+using namespace Rcpp;
+
 // [[Rcpp::export]]
 Rcpp::List bb(std::vector<double> price, int n, int sd = 2) {
     // calculate the simple moving average
diff --git a/src/init.c b/src/init.c
index d77eb45..8c86cae 100644
--- a/src/init.c
+++ b/src/init.c
@@ -28,4 +28,5 @@ static const R_CallMethodDef CallEntries[] = {
 void R_init_dmplot(DllInfo *dll) {
     R_registerRoutines(dll, NULL, CallEntries, NULL, NULL);
     R_useDynamicSymbols(dll, FALSE);
+    R_forceSymbols(dll, TRUE);
 }
\ No newline at end of file
diff --git a/src/sma-simple-moving-average.cpp b/src/sma-simple-moving-average.cpp
index 606d425..736cad9 100644
--- a/src/sma-simple-moving-average.cpp
+++ b/src/sma-simple-moving-average.cpp
@@ -1,4 +1,6 @@
 #include <Rcpp.h>
+// [[Rcpp::interfaces(r, cpp)]]
+
 #include <vector>
 
 using namespace Rcpp;