diff --git a/build.sh b/build.sh
index 27e4268..51bb745 100755
--- a/build.sh
+++ b/build.sh
@@ -1,39 +1,42 @@
 #!/bin/sh -e
 
-opts="-O2 -g0 -DNDEBUG -Wall -Wextra -s"
+CC=${CC:-gcc}
+CXX=${CXX:-g++}
+
+opts="-O2 -g0 -DNDEBUG -Wall -Wextra"
 [ -n "$DEBUG" ] && opts="-O0 -g3 -Wall -Wextra";
 
 build_gsr_kms_server() {
     dependencies="libdrm"
     includes="$(pkg-config --cflags $dependencies)"
     libs="$(pkg-config --libs $dependencies) -ldl"
-    gcc -c kms/server/kms_server.c $opts $includes
-    gcc -o gsr-kms-server -O2 kms_server.o $libs $opts
+    $CC -c kms/server/kms_server.c $opts $includes
+    $CC -o gsr-kms-server -O2 kms_server.o $libs $opts
 }
 
 build_gsr() {
     dependencies="libavcodec libavformat libavutil x11 xcomposite xrandr xfixes libpulse libswresample libavfilter libva libcap"
     includes="$(pkg-config --cflags $dependencies)"
     libs="$(pkg-config --libs $dependencies) -ldl -pthread -lm"
-    gcc -c src/capture/capture.c $opts $includes
-    gcc -c src/capture/nvfbc.c $opts $includes
-    gcc -c src/capture/xcomposite_cuda.c $opts $includes
-    gcc -c src/capture/xcomposite_vaapi.c $opts $includes
-    gcc -c src/capture/kms_vaapi.c $opts $includes
-    gcc -c kms/client/kms_client.c $opts $includes
-    gcc -c src/egl.c $opts $includes
-    gcc -c src/cuda.c $opts $includes
-    gcc -c src/xnvctrl.c $opts $includes
-    gcc -c src/overclock.c $opts $includes
-    gcc -c src/window_texture.c $opts $includes
-    gcc -c src/shader.c $opts $includes
-    gcc -c src/color_conversion.c $opts $includes
-    gcc -c src/cursor.c $opts $includes
-    gcc -c src/utils.c $opts $includes
-    gcc -c src/library_loader.c $opts $includes
-    g++ -c src/sound.cpp $opts $includes
-    g++ -c src/main.cpp $opts $includes
-    g++ -o gpu-screen-recorder -O2 capture.o nvfbc.o kms_client.o egl.o cuda.o xnvctrl.o overclock.o window_texture.o shader.o color_conversion.o cursor.o utils.o library_loader.o xcomposite_cuda.o xcomposite_vaapi.o kms_vaapi.o sound.o main.o $libs $opts
+    $CC -c src/capture/capture.c $opts $includes
+    $CC -c src/capture/nvfbc.c $opts $includes
+    $CC -c src/capture/xcomposite_cuda.c $opts $includes
+    $CC -c src/capture/xcomposite_vaapi.c $opts $includes
+    $CC -c src/capture/kms_vaapi.c $opts $includes
+    $CC -c kms/client/kms_client.c $opts $includes
+    $CC -c src/egl.c $opts $includes
+    $CC -c src/cuda.c $opts $includes
+    $CC -c src/xnvctrl.c $opts $includes
+    $CC -c src/overclock.c $opts $includes
+    $CC -c src/window_texture.c $opts $includes
+    $CC -c src/shader.c $opts $includes
+    $CC -c src/color_conversion.c $opts $includes
+    $CC -c src/cursor.c $opts $includes
+    $CC -c src/utils.c $opts $includes
+    $CC -c src/library_loader.c $opts $includes
+    $CXX -c src/sound.cpp $opts $includes
+    $CXX -c src/main.cpp $opts $includes
+    $CXX -o gpu-screen-recorder -O2 capture.o nvfbc.o kms_client.o egl.o cuda.o xnvctrl.o overclock.o window_texture.o shader.o color_conversion.o cursor.o utils.o library_loader.o xcomposite_cuda.o xcomposite_vaapi.o kms_vaapi.o sound.o main.o $libs $opts
 }
 
 build_gsr_kms_server
diff --git a/install.sh b/install.sh
index f898534..563a3b6 100755
--- a/install.sh
+++ b/install.sh
@@ -6,6 +6,8 @@ cd "$script_dir"
 [ $(id -u) -ne 0 ] && echo "You need root privileges to run the install script" && exit 1
 
 ./build.sh
+strip gsr-kms-server
+strip gpu-screen-recorder
 rm -f "/usr/local/bin/gpu-screen-recorder"
 install -Dm755 "gsr-kms-server" "/usr/bin/gsr-kms-server"
 install -Dm755 "gpu-screen-recorder" "/usr/bin/gpu-screen-recorder"
diff --git a/src/main.cpp b/src/main.cpp
index f24a3f0..9515d8d 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -732,20 +732,26 @@ static bool is_hex_num(char c) {
 }
 
 static bool contains_non_hex_number(const char *str) {
+    bool hex_start = false;
     size_t len = strlen(str);
     if(len >= 2 && memcmp(str, "0x", 2) == 0) {
         str += 2;
         len -= 2;
+        hex_start = true;
     }
 
+    bool is_hex = false;
     for(size_t i = 0; i < len; ++i) {
         char c = str[i];
         if(c == '\0')
             return false;
         if(!is_hex_num(c))
             return true;
+        if((c >= 'A' && c <= 'F') || (c >= 'a' && c <= 'f'))
+            is_hex = true;
     }
-    return false;
+
+    return is_hex && !hex_start;
 }
 
 static std::string get_date_str() {