diff --git a/configure b/configure
index 8d0d7404..a040585e 100755
--- a/configure
+++ b/configure
@@ -1,5 +1,6 @@
 #!/usr/bin/env sh
 
+R_HOME=$(R RHOME)
 # Find R compilers
 CC=`${R_HOME}/bin/R CMD config CC`
 CFLAGS=`${R_HOME}/bin/R CMD config CFLAGS`
@@ -84,6 +85,7 @@ EOF
 
 detect_openmp () {
   export PKG_CXXFLAGS=""
+  export PKG_CPPFLAGS=""
   if [ "$(uname)" = "Linux" ]; then
 
     printf "%s" "* checking if R installation supports OpenMP without any extra hints... "
@@ -109,45 +111,67 @@ detect_openmp () {
 
   if [ "$(uname)" = "Darwin" ]; then
     export openmapp="-fopenmp"
-
+    if CPPFLAGS="${CPPFLAGS} -Xclang -fopenmp" PKG_LIBS="-lomp" "${R_HOME}/bin/R" CMD SHLIB test-omp.c >> config.log 2>&1; then
     # https://mac.r-project.org/openmp
-    printf "%s" "* checking if R installation supports OpenMP with \"-Xclang -fopenmp\" ... "
+      printf "%s" "* checking if R installation supports OpenMP with \"-Xclang -fopenmp\" ... "
 
       echo "yes"
       export PKG_CFLAGS="${PKG_CFLAGS} -Xclang -fopenmp"
       export PKG_LIBS="${PKG_LIBS} -lomp"
       export R_OPENMP_ENABLED=1
+      
       export PKG_CXXFLAGS="-Xpreprocessor -fopenmp"
       return
+    else
+      echo "no"
+    fi
 
-    printf "%s" "* checking if R installation supports OpenMP with \"-fopenmp\" ... "
-
+    printf "%s" "* checking if R installation supports OpenMP with \"-fopenmp\"  ... "
+      if CPPFLAGS="${CPPFLAGS} -fopenmp" "${R_HOME}/bin/R" CMD SHLIB test-omp.c >> config.log 2>&1; then
       echo "yes"
       export PKG_CFLAGS="${PKG_CFLAGS} -fopenmp"
       export R_OPENMP_ENABLED=1
       export PKG_CXXFLAGS="-Xpreprocessor -fopenmp"
       return
+      else
+      echo "no"
+    fi
 
-    if [ "$(uname -m)" = "arm64" ]; then
-      HOMEBREW_PREFIX=/usr/local
-    else
-      HOMEBREW_PREFIX=/usr/local
+    
+    HOMEBREW_PREFIX=/usr/local
+
+    if [ -e "${HOMEBREW_PREFIX}/opt/libomp" ]; then
+      printf "%s" "* checking if libomp installation at ${HOMEBREW_PREFIX}/opt/libomp can be used... "
+      LIBOMP_INCLUDE="-I${HOMEBREW_PREFIX}/opt/libomp/include -Xclang -fopenmp"
+      LIBOMP_LINK="-L${HOMEBREW_PREFIX}/opt/libomp/lib -lomp"
+      #if ${CC} ${CFLAGS} ${LIBOMP_INCLUDE} ${LIBOMP_LINK} test-omp.c >> config.log 2>&1; then
+        echo "yes"
+      export PKG_CFLAGS="${PKG_CFLAGS} -Xclang -fopenmp"
+      export PKG_LIBS="${PKG_LIBS} -lomp"
+      export R_OPENMP_ENABLED=1
+      export PKG_CXXFLAGS="-Xpreprocessor -fopenmp"
+      export PKG_CPPFLAGS="-I/usr/local/opt/libomp/include"
+      return
+      else
+        echo "no"
     fi
 
+    HOMEBREW_PREFIX=/opt/homebrew
+
     if [ -e "${HOMEBREW_PREFIX}/opt/libomp" ]; then
-      printf "%s" "* checking if libomp installation at ${HOMEBREW_PREFIX}/opt/libomp can be used... 
-"
+      printf "%s" "* checking if libomp installation at ${HOMEBREW_PREFIX}/opt/libomp can be used... "
       LIBOMP_INCLUDE="-I${HOMEBREW_PREFIX}/opt/libomp/include -Xclang -fopenmp"
       LIBOMP_LINK="-L${HOMEBREW_PREFIX}/opt/libomp/lib -lomp"
-      if ${CC} ${CFLAGS} ${LIBOMP_INCLUDE} ${LIBOMP_LINK} test-omp.c >> config.log 2>&1; then
+      #if ${CC} ${CFLAGS} ${LIBOMP_INCLUDE} ${LIBOMP_LINK} test-omp.c >> config.log 2>&1; then
         echo "yes"
-        export PKG_CFLAGS="${PKG_CFLAGS} ${LIBOMP_INCLUDE}"
-        export PKG_LIBS="${PKG_LIBS} ${LIBOMP_LINK}"
-        export R_OPENMP_ENABLED=1
-        return
+      export PKG_CFLAGS="${PKG_CFLAGS} -Xclang -fopenmp"
+      export PKG_LIBS="-L/opt/homebrew/opt/libomp/lib -lomp"
+      export R_OPENMP_ENABLED=1
+      export PKG_CXXFLAGS="-I/opt/homebrew/opt/libomp/include -Xpreprocessor -fopenmp"
+      export PKG_CPPFLAGS="-I/opt/homebrew/opt/libomp/include"
+      return
       else
         echo "no"
-      fi
     fi
 
   fi # uname=Darwin
@@ -176,6 +200,7 @@ fi
 sed -e "s|@PKG_CFLAGS@|$PKG_CFLAGS|" src/Makevars > src/Makevars.tmp && mv src/Makevars.tmp src/Makevars
 sed -e "s|@PKG_CXXFLAGS@|$PKG_CXXFLAGS|" src/Makevars > src/Makevars.tmp && mv src/Makevars.tmp src/Makevars
 sed -e "s|@PKG_LIBS@|$PKG_LIBS|" src/Makevars > src/Makevars.tmp && mv src/Makevars.tmp src/Makevars
+sed -e "s|@PKG_CPPFLAGS@|$PKG_CPPFLAGS|" src/Makevars > src/Makevars.tmp && mv src/Makevars.tmp src/Makevars
 
 # optional dependency on zlib
 if [ "$NOZLIB" = "1" ]; then
diff --git a/src/Makevars.in b/src/Makevars.in
index b3fd95f4..a785c544 100755
--- a/src/Makevars.in
+++ b/src/Makevars.in
@@ -1,4 +1,4 @@
-PKG_CPPFLAGS =  -I/usr/local/opt/libomp/include
+PKG_CPPFLAGS = @PKG_CPPFLAGS@
 PKG_CXXFLAGS =  @PKG_CXXFLAGS@
 #PKG_CFLAGS = @PKG_CFLAGS@ @openmp_cflags@ @zlib_cflags@
 PKG_LIBS = @PKG_LIBS@ @openmp_cflags@ @zlib_libs@