diff --git a/v2/tools/tru64.jam b/v2/tools/tru64.jam
index 96726d4e4..c6c302ac7 100644
--- a/v2/tools/tru64.jam
+++ b/v2/tools/tru64.jam
@@ -143,9 +143,12 @@ actions compile.c
 
 # Note: DON'T disable warning 1133 -- the compiler is buggy and you
 # really can't ignore this one!
+#
+# The compiler is forced to compile the files as C++ (-x cxx) because
+# otherwise it will silently ignore files with no file extension.
 actions compile.c++
 {
-    $(CONFIG_COMMAND)  -c -std strict_ansi -nopure_cname -noimplicit_include -timplicit_local -ptr "$(<[1]:D)/cxx_repository" -msg_display_number -msg_disable 186,450,1115 $(OPTIONS) -D$(DEFINES) -I"$(INCLUDES)" -o "$(<)" "$(>)"
+    $(CONFIG_COMMAND) -x cxx -c -std strict_ansi -nopure_cname -noimplicit_include -timplicit_local -ptr "$(<[1]:D)/cxx_repository" -msg_display_number -msg_disable 186,450,1115 $(OPTIONS) -D$(DEFINES) -I"$(INCLUDES)" -o "$(<)" "$(>)"
 }
 
 # Always create archive from scratch. See the gcc toolet for rationale.