diff --git a/configure.in b/configure.in
index 2615325..43ad61e 100644
--- a/configure.in
+++ b/configure.in
@@ -26,6 +26,11 @@ LTCXX_FLAGS="--tag=CXX"
 AC_SUBST(LTC_FLAGS)
 AC_SUBST(LTCXX_FLAGS)
 
+AC_CHECK_PROGS([NASM],[nasm],none)
+if test "x$NASM" = "xnone" ;
+then
+    AC_MSG_ERROR([Cinelerra requires the nasm assembler])
+fi
 
 # hack for using nasm for .S files
 CCAS="\$(top_srcdir)/admin/nasm"