diff --git a/configure.ac b/configure.ac
index a17bcb072c..b9357d1d8a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -700,6 +700,9 @@ AC_ARG_ENABLE( debug,
      CFLAGS=`echo ${CFLAGS} | sed -e 's,-O.,,g'`
      # ...except for those the user wants.
      CFLAGS="${CFLAGS} -g ${USER_OPTIMIZATION}"
+     # Do the same for C++
+     CXXFLAGS=`echo ${CXXFLAGS} | sed -e 's,-O.,,g'`
+     CXXFLAGS="${CXXFLAGS} -g ${USER_OPTIMIZATION}"
      LDFLAGS="${LDFLAGS} -g"
      AC_DEFINE(DEBUG_MEMORY,1,[Enable debug memory])
   ],
@@ -709,6 +712,7 @@ AC_ARG_ENABLE( debug,
 AC_ARG_ENABLE( profile,
   [AS_HELP_STRING([--enable-profile],[compile with profiling set])],
   CFLAGS="${CFLAGS} -pg"
+  CXXFLAGS="${CFLAGS} -pg"
   LDFLAGS="${LDFLAGS} -pg")
 
 ### --------------------------------------------------------------------------
@@ -1148,6 +1152,7 @@ else
   then
     # We should always see these errors...
     AM_CFLAGS="${AM_CFLAGS} -Wall"
+    AM_CXXFLAGS="${AM_CXXFLAGS} -Wall"
   fi
 
 fi
@@ -1272,7 +1277,9 @@ AC_MSG_CHECKING(what extra warning flags to pass to the C compiler)
 if test ${GCC}x = yesx
 then
   warnFLAGS=
+  warnXXFLAGS=
   AM_CFLAGS="${AM_CFLAGS} -Wno-unused"
+  AM_CXXFLAGS="${AM_CXXFLAGS} -Wno-unused"
   # other flags...
   # These next two are included in the GNOME_COMPILE_WARNINGS
   #warnFLAGS="${warnFLAGS} -Wmissing-prototypes"
@@ -1294,12 +1301,13 @@ then
   AC_ARG_ENABLE(error-on-warning,
     [AS_HELP_STRING([--disable-error-on-warning],[disable treating compile warnings as errors])],
     [case "${enableval}" in
-       yes) warnFLAGS="${warnFLAGS} -Werror" ; gnc_error_on_warning=yes ;;
+       yes) warnFLAGS="${warnFLAGS} -Werror" ; warnXXFLAGS="${warnXXFLAGS} -Werror" ; gnc_error_on_warning=yes ;;
        no)  gnc_error_on_warning=no ;;
        *) AC_MSG_ERROR(bad value ${enableval} for --enable-error-on-warning) ;;
      esac],
     [ if test "${error_on_warning_as_default}" = "yes"; then
         warnFLAGS="${warnFLAGS} -Werror";
+        warnXXFLAGS="${warnXXFLAGS} -Werror";
         gnc_error_on_warning=auto
       else
         gnc_error_on_warning=no
@@ -1324,10 +1332,12 @@ then
     fi
   fi
   AM_CFLAGS="${warnFLAGS} ${AM_CFLAGS}"
+  AM_CXXFLAGS="${warnXXFLAGS} ${AM_CXXFLAGS}"
 else
   warnFLAGS=none
 fi
 AC_SUBST(AM_CFLAGS)
+AC_SUBST(AM_CXXFLAGS)
 AC_MSG_RESULT($warnFLAGS)
 
 ### --------------------------------------------------------------------------
@@ -1551,6 +1561,7 @@ AC_MSG_RESULT([
   Extra Warnings ....... : $warnFLAGS
   CPPFLAGS ............. : $CPPFLAGS
   CFLAGS ............... : $CFLAGS
+  CXXFLAGS ............. : $CXXFLAGS
   LDFLAGS .............. : $LDFLAGS
   prefix................ : ${prefix}
 
diff --git a/src/engine/test/Makefile.am b/src/engine/test/Makefile.am
index aedaf1f198..515a3a7984 100644
--- a/src/engine/test/Makefile.am
+++ b/src/engine/test/Makefile.am
@@ -114,8 +114,9 @@ noinst_PROGRAMS = ${TEST_PROGS} ${CHECK_PROGS}
 test_engine_SOURCES = \
 	test-engine.c \
 	utest-Account.c \
-    utest-Budget.c \
-	utest-Invoice.c
+	utest-Budget.c \
+	utest-Invoice.c \
+	dummy.cpp
 
 test_engine_LDADD = \
 	libutest-Split.la \
@@ -132,9 +133,9 @@ noinst_LTLIBRARIES = \
 	libutest-Trans.la
 
 libutest_Split_la_SOURCES = \
-	utest-Split.c \
+	utest-Split.cpp \
 	${top_srcdir}/src/libqof/qof/gnc-numeric.cpp
-libutest_Split_la_CFLAGS = -xc++ -Wno-deprecated-writable-strings
+libutest_Split_la_CXXFLAGS = -Wno-write-strings $(AM_CXXFLAGS)
 
 libutest_Split_la_LIBADD = $(LDADD)
 
diff --git a/src/engine/test/dummy.cpp b/src/engine/test/dummy.cpp
new file mode 100644
index 0000000000..78752143ea
--- /dev/null
+++ b/src/engine/test/dummy.cpp
@@ -0,0 +1,2 @@
+// This is a dummy source file since we need a C++ file in test_engine so
+// it will be linked as a C++ program.
diff --git a/src/engine/test/utest-Split.c b/src/engine/test/utest-Split.cpp
similarity index 100%
rename from src/engine/test/utest-Split.c
rename to src/engine/test/utest-Split.cpp
diff --git a/src/libqof/qof/Makefile.am b/src/libqof/qof/Makefile.am
index a86c0e8a0e..995c6ee258 100644
--- a/src/libqof/qof/Makefile.am
+++ b/src/libqof/qof/Makefile.am
@@ -86,7 +86,10 @@ libmd5_la_SOURCES = md5.c
 libmd5_la_CFLAGS = -fno-strict-aliasing
 
 libgnc_qof_la_LIBADD += libmd5.la
-libgnc_qof_la_CFLAGS = -xc++ -Wall -Werror
+libgnc_qof_la_CFLAGS = -xc++ $(AM_CXXFLAGS)
+# Since we asked for the C++ compiler, give it the C++ flags, not the C flags
+# which may not be legal in C++
+CFLAGS = $(CXXFLAGS)
 
 EXTRA_DIST += \
   qofmath128.c