diff --git a/eo/app/gpsymreg/Makefile.am b/eo/app/gpsymreg/Makefile.am
index 338f1492..a3877197 100644
--- a/eo/app/gpsymreg/Makefile.am
+++ b/eo/app/gpsymreg/Makefile.am
@@ -17,7 +17,7 @@ bin_PROGRAMS = gpsymreg
 
 ###############################################################################
 
-gpsymreg_SOURCES = main.cc
+gpsymreg_SOURCES = main.cpp
 gpsymreg_DEPENDENCIES = $(DEPS)
 gpsymreg_LDFLAGS = -lm
 gpsymreg_LDADD = $(LDADDS)
diff --git a/eo/app/gpsymreg/main.cc b/eo/app/gpsymreg/main.cpp
similarity index 100%
rename from eo/app/gpsymreg/main.cc
rename to eo/app/gpsymreg/main.cpp