diff --git a/tools/Makefile.am b/tools/Makefile.am
index d6386b4a..5afbacc7 100644
--- a/tools/Makefile.am
+++ b/tools/Makefile.am
@@ -1,9 +1,9 @@
-EXTRA_DIST = curve_keygen.c 
+EXTRA_DIST = curve_keygen.cpp
 
 INCLUDES = -I$(top_srcdir)/include
 
 bin_PROGRAMS = curve_keygen
 
 curve_keygen_LDADD = $(top_builddir)/src/libzmq.la
-curve_keygen_SOURCES = curve_keygen.c
+curve_keygen_SOURCES = curve_keygen.cpp
 
diff --git a/tools/curve_keygen.c b/tools/curve_keygen.cpp
similarity index 100%
rename from tools/curve_keygen.c
rename to tools/curve_keygen.cpp