diff --git a/configure.ac b/configure.ac
index 6c6ca2e..ad6bf9a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -102,6 +102,7 @@
         [PKG_CHECK_MODULES(UHD, uhd >= 003.005.004)]
     )
     AC_DEFINE(USE_UHD, 1, All UHD versions)
+    PKG_CHECK_MODULES(FFTWF, fftw3f)
 ])
 
 AS_IF([test "x$with_singledb" = "xyes"], [