diff --git a/libs/spandsp/src/spandsp/fir.h b/libs/spandsp/src/spandsp/fir.h
index 85be5d2a6f..554a36c372 100644
--- a/libs/spandsp/src/spandsp/fir.h
+++ b/libs/spandsp/src/spandsp/fir.h
@@ -38,6 +38,8 @@
 #include "mmx.h"
 #endif
 
+#include "alloc.h"
+
 /*!
     16 bit integer FIR descriptor. This defines the working state for a single
     instance of an FIR filter using 16 bit integer coefficients.