diff --git a/CMakeLists.txt b/CMakeLists.txt
index 14b1787..995b030 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -257,6 +257,7 @@ message(STATUS "Compiling with support for: ${apilist}")
 # PkgConfig file
 string(REPLACE ";" " " req "${PKGCONFIG_REQUIRES}")
 string(REPLACE ";" " " api "${API_DEFS}")
+set(prefix ${CMAKE_INSTALL_PREFIX})
 configure_file("rtaudio.pc.in" "rtaudio.pc" @ONLY)
 
 # Add install rule.
diff --git a/configure.ac b/configure.ac
index d3a0cc4..266ff48 100644
--- a/configure.ac
+++ b/configure.ac
@@ -86,8 +86,8 @@ AC_CHECK_HEADERS(sys/ioctl.h unistd.h)
 AS_IF([test "x${GXX}" = "xyes" ], [
   CXXFLAGS="-Wall -Wextra ${CXXFLAGS}"
   AS_IF([ test "x${enable_debug}" = "xyes" ], [
-    # Add -Werror in debug mode
-    CXXFLAGS="-Werror ${CXXFLAGS}"
+    # Add -Werror in debug mode (except unused-function)
+    CXXFLAGS="-Werror -Wno-error=unused-function ${CXXFLAGS}"
   ], [
     # hide private symbols in non-debug mode
     visibility="-fvisibility=hidden"
diff --git a/rtaudio.pc.in b/rtaudio.pc.in
index 7627780..0e81090 100644
--- a/rtaudio.pc.in
+++ b/rtaudio.pc.in
@@ -1,4 +1,4 @@
-prefix=@CMAKE_INSTALL_PREFIX@
+prefix=@prefix@
 exec_prefix=${prefix}
 libdir=${exec_prefix}/lib
 includedir=${prefix}/include/rtaudio        
diff --git a/tests/audioprobe.cpp b/tests/audioprobe.cpp
index 1b93908..c83d3a5 100644
--- a/tests/audioprobe.cpp
+++ b/tests/audioprobe.cpp
@@ -46,6 +46,7 @@ int main()
     info = audio.getDeviceInfo(i);
 
     std::cout << "\nDevice Name = " << info.name << '\n';
+    std::cout << "Device ID = " << i << '\n';
     if ( info.probed == false )
       std::cout << "Probe Status = UNsuccessful\n";
     else {