diff --git a/configure.in b/configure.in
index e936cc7a..ae944b4c 100644
--- a/configure.in
+++ b/configure.in
@@ -55,13 +55,6 @@ fi
 
 # Checks for libraries.
 AC_CHECK_LIB([pthread], [pthread_create])
-# If using GNU C/C++ and static linking, libstdc++ must be available.
-if test "x$gnu_compilers" = "xyes" -a "x$enable_shared" = "xno"; then
-    # libstdc++ depends on libm on some platforms
-    AC_CHECK_LIB([m], [main])
-    AC_CHECK_LIB([stdc++], [main], ,
-        [AC_MSG_ERROR([cannot link with -lstdc++])])
-fi
 
 # Extra CXXFLAGS are appended at the end of CXXFLAGS for libzmq.
 LIBZMQ_EXTRA_CXXFLAGS=""
diff --git a/perf/Makefile.am b/perf/Makefile.am
index d48dceec..fe35ff3d 100644
--- a/perf/Makefile.am
+++ b/perf/Makefile.am
@@ -7,19 +7,19 @@ endif
 noinst_PROGRAMS = local_lat remote_lat local_thr remote_thr $(PGM_EXAMPLES_BINS)
 
 local_lat_LDADD = $(top_builddir)/src/libzmq.la
-local_lat_SOURCES = local_lat.c
+local_lat_SOURCES = local_lat.cpp
 local_lat_CXXFLAGS = -Wall -pedantic -Werror
 
 remote_lat_LDADD = $(top_builddir)/src/libzmq.la
-remote_lat_SOURCES = remote_lat.c
+remote_lat_SOURCES = remote_lat.cpp
 remote_lat_CXXFLAGS = -Wall -pedantic -Werror
 
 local_thr_LDADD = $(top_builddir)/src/libzmq.la
-local_thr_SOURCES = local_thr.c
+local_thr_SOURCES = local_thr.cpp
 local_thr_CXXFLAGS = -Wall -pedantic -Werror
 
 remote_thr_LDADD = $(top_builddir)/src/libzmq.la
-remote_thr_SOURCES = remote_thr.c
+remote_thr_SOURCES = remote_thr.cpp
 remote_thr_CXXFLAGS = -Wall -pedantic -Werror
 
 if BUILD_PGM_EXAMPLES
diff --git a/perf/local_lat.c b/perf/local_lat.cpp
similarity index 99%
rename from perf/local_lat.c
rename to perf/local_lat.cpp
index 0114b233..9297137a 100644
--- a/perf/local_lat.c
+++ b/perf/local_lat.cpp
@@ -25,7 +25,7 @@ int main (int argc, char *argv [])
 {
     const char *bind_to;
     int roundtrip_count;
-    int message_size;
+    size_t message_size;
     void *ctx;
     void *s;
     int rc;
diff --git a/perf/local_thr.c b/perf/local_thr.cpp
similarity index 99%
rename from perf/local_thr.c
rename to perf/local_thr.cpp
index 908bbe3f..b612157d 100644
--- a/perf/local_thr.c
+++ b/perf/local_thr.cpp
@@ -25,7 +25,7 @@ int main (int argc, char *argv [])
 {
     const char *bind_to;
     int message_count;
-    int message_size;
+    size_t message_size;
     void *ctx;
     void *s;
     int rc;
diff --git a/perf/remote_lat.c b/perf/remote_lat.cpp
similarity index 99%
rename from perf/remote_lat.c
rename to perf/remote_lat.cpp
index 6214ce8b..df18b562 100644
--- a/perf/remote_lat.c
+++ b/perf/remote_lat.cpp
@@ -26,7 +26,7 @@ int main (int argc, char *argv [])
 {
     const char *connect_to;
     int roundtrip_count;
-    int message_size;
+    size_t message_size;
     void *ctx;
     void *s;
     int rc;
diff --git a/perf/remote_thr.c b/perf/remote_thr.cpp
similarity index 100%
rename from perf/remote_thr.c
rename to perf/remote_thr.cpp