diff --git a/debian/install-openssl.sh b/debian/install-openssl.sh
index 0963bdb5..b1b463cb 100755
--- a/debian/install-openssl.sh
+++ b/debian/install-openssl.sh
@@ -171,6 +171,10 @@ main() {
         exit 0
     fi
 
+    if [ -n "output_dir" ]; then
+        output_dir=$(realpath $output_dir)
+    fi
+
     work_dir=$(mktemp -d)
     printf "Working directory: $work_dir\n"
     pushd $work_dir 2>&1 > /dev/null
@@ -183,13 +187,13 @@ main() {
         openssl_install
     fi
 
-    if [ -n "$output_dir" ] && [ "$output_dir" != ".." ]; then
+    if [ -n "$output_dir" ]; then
         if [ ! -d "$output_dir" ]; then
             printf "Creating output directory: $output_dir\n"
             mkdir -p "$output_dir"
         fi
-        cp ../openssl*.deb $output_dir
-        cp ../libssl*.deb $output_dir
+        cp ../openssl*.deb $output_dir || true
+        cp ../libssl*.deb $output_dir || true
     else
         printf "No output directory specified, packages stored in $work_dir\n"
     fi
diff --git a/debian/install-wolfprov.sh b/debian/install-wolfprov.sh
index 62ef9380..bf51ddda 100755
--- a/debian/install-wolfprov.sh
+++ b/debian/install-wolfprov.sh
@@ -188,6 +188,10 @@ main() {
         exit 1
     fi
 
+    if [ -n "output_dir" ]; then
+        output_dir=$(realpath $output_dir)
+    fi
+
     work_dir=$(mktemp -d)
     printf "Working directory: $work_dir\n"
     pushd $work_dir 2>&1 > /dev/null
@@ -199,12 +203,12 @@ main() {
         wolfprov_install
     fi
 
-    if [ -n "$output_dir" ] && [ "$output_dir" != ".." ]; then
+    if [ -n "$output_dir" ]; then
         if [ ! -d "$output_dir" ]; then
             printf "Creating output directory: $output_dir\n"
             mkdir -p "$output_dir"
         fi
-        cp ../*.* $output_dir
+        cp ../*.* $output_dir || true
     else
         printf "No output directory specified, packages stored in $work_dir\n"
     fi
diff --git a/debian/rules b/debian/rules
index a5ab2d25..df5378d5 100755
--- a/debian/rules
+++ b/debian/rules
@@ -32,19 +32,35 @@ endif
 
 # Debug build flag
 WOLFPROV_DEBUG?=0
+DEBUG_FLAG=
 ifeq ($(WOLFPROV_DEBUG),1)
   VARIANT           := $(VARIANT)-debug
   VARIANT_DESC      := $(VARIANT_DESC) with debug logs
   VERSION           := $(VERSION)-debug
+  DEBUG_FLAG        := --enable-debug
+endif
+
+ifeq ($(DEB_CFLAGS_APPEND),)
+export PKG_CONFIG_LIBDIR # value comes from outer environment 
+export PKG_CONFIG_DIR := 
+export PKG_CONFIG_PATH :=
 endif
 
 override_dh_auto_configure:
 	./autogen.sh
-ifneq ($(WOLFPROV_DEBUG),0)
-	./configure --enable-debug
-else
-	./configure
-endif
+	@if [ -n "$(DEB_CFLAGS_APPEND)" ]; then \
+		printf "DEB_CFLAGS_APPEND: %s\n" $(DEB_CFLAGS_APPEND); \
+		printf "DEB_CPPFLAGS_APPEND: %s\n" $(DEB_CPPFLAGS_APPEND); \
+		printf "DEB_CXXFLAGS_APPEND: %s\n" $(DEB_CXXFLAGS_APPEND); \
+		printf "DEB_LDFLAGS_APPEND: %s\n" $(DEB_LDFLAGS_APPEND); \
+		@echo "PKG_CONFIG_LIBDIR=$(PKG_CONFIG_LIBDIR)" \
+		# ensure only our .pc dirs are searched: \
+		PKG_CONFIG_DIR= PKG_CONFIG_PATH= \
+		PKG_CONFIG_LIBDIR="$(PKG_CONFIG_LIBDIR)" \
+		dh_auto_configure -- $(DEBUG_FLAG); \
+	else \
+		./configure $(DEBUG_FLAG); \
+	fi
 
 override_dh_auto_build:
 	$(MAKE)
@@ -82,4 +98,23 @@ override_dh_auto_clean:
 	rm -rf test/standalone/tests/.libs
 
 override_dh_auto_test:
-	$(MAKE) test
+	@if [ -n "$(DEB_LDFLAGS_APPEND)" ]; then \
+		# If DEB_LDFLAGS_APPEND is set, it usually means the \
+		# build system is using a custom library path, rather \
+		# than the system path. So let's set up LD_LIBRARY_PATH \
+		# to use it when running `make test`. \
+		echo "Setting up LD_LIBRARY_PATH from DEB_LDFLAGS_APPEND"; \
+		LD_LIBRARY_PATH="$$(echo $(DEB_LDFLAGS_APPEND) | \
+		  grep -oE -- '-L[^ ]+' | sed 's/^-L//' | awk '!seen[$$0]++' | paste -sd: -)" \
+		$(MAKE) test; \
+	else \
+		$(MAKE) test; \
+	fi
+
+override_dh_shlibdeps:
+	@if [ -n "$(DEB_LDFLAGS_APPEND)" ]; then \
+		# Skip shlibdeps for now since we're using a custom library path \
+		: \
+	else \
+		dh_shlibdeps; \
+	fi
diff --git a/scripts/build-wolfprovider.sh b/scripts/build-wolfprovider.sh
index 1f1c8f3c..c8de5014 100755
--- a/scripts/build-wolfprovider.sh
+++ b/scripts/build-wolfprovider.sh
@@ -148,6 +148,8 @@ fi
 if [ -n "$build_debian" ]; then
     set -e
 
+    DEB_OUTPUT_DIR=$(realpath '..')
+
     echo "Building Debian package..."
     WOLFSSL_OPTS=
     WOLFPROV_OPTS=
@@ -161,12 +163,42 @@ if [ -n "$build_debian" ]; then
         WOLFSSL_OPTS+=" --fips"
         WOLFPROV_OPTS+=" --fips"
     fi
+    if [ "$WOLFPROV_REPLACE_DEFAULT" = "1" ]; then
+        OPENSSL_OPTS+=" --replace-default"
+    fi
+
+    # wolfSSL and OpenSSL are independent and must be built first
+    debian/install-wolfssl.sh $WOLFSSL_OPTS --no-install -r $DEB_OUTPUT_DIR
+    debian/install-openssl.sh $OPENSSL_OPTS --no-install $DEB_OUTPUT_DIR
+
+    # wolfProvider depends on wolfSSL and OpenSSL headers and libraries.
+    # We don't want to install them locally, so we unpack them to 
+    # temp dirs and reference those in the build.
+
+    # Unpack the wolfssl packages to a temporary directory
+    wolfssl_dev_dir=$(mktemp -d)
+    dpkg -x $DEB_OUTPUT_DIR/libwolfssl_*.deb $wolfssl_dev_dir
+    dpkg -x $DEB_OUTPUT_DIR/libwolfssl-dev_*.deb $wolfssl_dev_dir
+    # Unpack the libssl-dev package to a temporary directory
+    openssl_dev_dir=$(mktemp -d)
+    dpkg -x $DEB_OUTPUT_DIR/openssl_*.deb $openssl_dev_dir
+    dpkg -x $DEB_OUTPUT_DIR/libssl-dev_*.deb $openssl_dev_dir
+
+    export DEB_HOST_MULTIARCH=$(dpkg-architecture -qDEB_HOST_MULTIARCH)
+
+    printf "wolfssl_dev_dir: %s\n" $wolfssl_dev_dir
+    printf "wolfssl_dev_dir libs: %s\n" $(ls $wolfssl_dev_dir/usr/lib/$DEB_HOST_MULTIARCH)
+    printf "openssl_dev_dir: %s\n" $openssl_dev_dir
+    printf "openssl_dev_dir libs: %s\n" $(ls $openssl_dev_dir/usr/lib/$DEB_HOST_MULTIARCH)
+
+    export DEB_CFLAGS_APPEND="-I$wolfssl_dev_dir/usr/include -I$openssl_dev_dir/usr/include"
+    export DEB_CPPFLAGS_APPEND="-I$wolfssl_dev_dir/usr/include -I$openssl_dev_dir/usr/include"
+    export DEB_CXXFLAGS_APPEND="-I$wolfssl_dev_dir/usr/include -I$openssl_dev_dir/usr/include"
+    export DEB_LDFLAGS_APPEND="-L$wolfssl_dev_dir/usr/lib/$DEB_HOST_MULTIARCH -L$openssl_dev_dir/usr/lib/$DEB_HOST_MULTIARCH"
+    export PKG_CONFIG_LIBDIR=$wolfssl_dev_dir/usr/lib/$DEB_HOST_MULTIARCH/pkgconfig:$openssl_dev_dir/usr/lib/$DEB_HOST_MULTIARCH/pkgconfig
+    debian/install-wolfprov.sh $WOLFPROV_OPTS --no-install $DEB_OUTPUT_DIR
 
-    # Must install wolfSSL locally since it is needed to build wolfProvider
-    debian/install-wolfssl.sh $WOLFSSL_OPTS -r ..
-    # Always build replace-default mode for openssl. Use the standard one from apt.
-    debian/install-openssl.sh $OPENSSL_OPTS --replace-default ..
-    debian/install-wolfprov.sh $WOLFPROV_OPTS --no-install
+    printf "Debian packages built in: %s\n" $DEB_OUTPUT_DIR
 
     exit 0
 fi