diff --git a/lib-src/portaudio-v19/Makefile.in b/lib-src/portaudio-v19/Makefile.in
index 472d87345..8a208765a 100644
--- a/lib-src/portaudio-v19/Makefile.in
+++ b/lib-src/portaudio-v19/Makefile.in
@@ -22,6 +22,7 @@ CFLAGS = -I$(top_srcdir)/include -I$(top_srcdir)/src/common -I$(top_srcdir)/src/
 LIBS = @LIBS@
 AR = @AR@
 RANLIB = @RANLIB@
+SHELL = @SHELL@
 LIBTOOL = @LIBTOOL@
 INSTALL = @INSTALL@
 INSTALL_DATA = @INSTALL_DATA@