diff --git a/apps/plugins/fft/math.c b/apps/plugins/fft/math.c
deleted file mode 100644
index c00804fcc8..0000000000
--- a/apps/plugins/fft/math.c
+++ /dev/null
@@ -1,13 +0,0 @@
-#include "math.h"
-
-int64_t fsqrt64(int64_t a, unsigned int fracbits)
-{
-    int64_t b = a/2 + (1 << fracbits); /* initial approximation */
-    unsigned int n;
-    const unsigned int iterations = 3; /* very rough approximation */
-
-    for (n = 0; n < iterations; ++n)
-        b = (b + (((int64_t)(a) << fracbits)/b))/2;
-
-    return b;
-}